diff --git a/backend/src/features/documents/data/documents.repository.ts b/backend/src/features/documents/data/documents.repository.ts
index 0f9ca1e..e0d101e 100644
--- a/backend/src/features/documents/data/documents.repository.ts
+++ b/backend/src/features/documents/data/documents.repository.ts
@@ -90,6 +90,64 @@ export class DocumentsRepository {
     return res.rows.map(row => this.mapDocumentRecord(row));
   }
 
+  async batchInsert(
+    documents: Array<{
+      id: string;
+      userId: string;
+      vehicleId: string;
+      documentType: DocumentType;
+      title: string;
+      notes?: string | null;
+      details?: any;
+      issuedDate?: string | null;
+      expirationDate?: string | null;
+      emailNotifications?: boolean;
+      scanForMaintenance?: boolean;
+    }>,
+    client?: any
+  ): Promise<DocumentRecord[]> {
+    if (documents.length === 0) {
+      return [];
+    }
+
+    // Multi-value INSERT for performance (avoids N round-trips)
+    const queryClient = client || this.db;
+    const placeholders: string[] = [];
+    const values: any[] = [];
+    let paramCount = 1;
+
+    documents.forEach((doc) => {
+      const docParams = [
+        doc.id,
+        doc.userId,
+        doc.vehicleId,
+        doc.documentType,
+        doc.title,
+        doc.notes ?? null,
+        doc.details ?? null,
+        doc.issuedDate ?? null,
+        doc.expirationDate ?? null,
+        doc.emailNotifications ?? false,
+        doc.scanForMaintenance ?? false
+      ];
+
+      const placeholder = `($${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++})`;
+      placeholders.push(placeholder);
+      values.push(...docParams);
+    });
+
+    const query = `
+      INSERT INTO documents (
+        id, user_id, vehicle_id, document_type, title, notes, details, issued_date, expiration_date, email_notifications, scan_for_maintenance
+      )
+      VALUES ${placeholders.join(', ')}
+      RETURNING *
+    `;
+
+    const result = await queryClient.query(query, values);
+    return result.rows.map((row: any) => this.mapDocumentRecord(row));
+  }
+
   async softDelete(id: string, userId: string): Promise<void> {
     await this.db.query(`UPDATE documents SET deleted_at = NOW() WHERE id = $1 AND user_id = $2`, [id, userId]);
   }
diff --git a/backend/src/features/fuel-logs/data/fuel-logs.repository.ts b/backend/src/features/fuel-logs/data/fuel-logs.repository.ts
index 1e03cb5..934936e 100644
--- a/backend/src/features/fuel-logs/data/fuel-logs.repository.ts
+++ b/backend/src/features/fuel-logs/data/fuel-logs.repository.ts
@@ -148,6 +148,52 @@ export class FuelLogsRepository {
     return this.mapRow(result.rows[0]);
   }
 
+  async batchInsert(
+    logs: Array<CreateFuelLogRequest & { userId: string }>,
+    client?: any
+  ): Promise<FuelLog[]> {
+    if (logs.length === 0) {
+      return [];
+    }
+
+    // Multi-value INSERT for performance (avoids N round-trips)
+    const queryClient = client || this.pool;
+    const placeholders: string[] = [];
+    const values: any[] = [];
+    let paramCount = 1;
+
+    logs.forEach((log) => {
+      const logParams = [
+        log.userId,
+        log.vehicleId,
+        log.date,
+        log.odometer,
+        log.gallons,
+        log.pricePerGallon,
+        log.totalCost,
+        log.station,
+        log.location,
+        log.notes
+      ];
+
+      const placeholder = `($${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++})`;
+      placeholders.push(placeholder);
+      values.push(...logParams);
+    });
+
+    const query = `
+      INSERT INTO fuel_logs (
+        user_id, vehicle_id, date, odometer, gallons,
+        price_per_gallon, total_cost, station, location, notes
+      )
+      VALUES ${placeholders.join(', ')}
+      RETURNING *
+    `;
+
+    const result = await queryClient.query(query, values);
+    return result.rows.map((row: any) => this.mapRow(row));
+  }
+
   async delete(id: string): Promise<boolean> {
     const query = 'DELETE FROM fuel_logs WHERE id = $1';
     const result = await this.pool.query(query, [id]);
diff --git a/backend/src/features/maintenance/data/maintenance.repository.ts b/backend/src/features/maintenance/data/maintenance.repository.ts
index dffaec9..24758e6 100644
--- a/backend/src/features/maintenance/data/maintenance.repository.ts
+++ b/backend/src/features/maintenance/data/maintenance.repository.ts
@@ -172,6 +172,62 @@ export class MaintenanceRepository {
     return res.rows[0] ? this.mapMaintenanceRecord(res.rows[0]) : null;
   }
 
+  async batchInsertRecords(
+    records: Array<{
+      id: string;
+      userId: string;
+      vehicleId: string;
+      category: MaintenanceCategory;
+      subtypes: string[];
+      date: string;
+      odometerReading?: number | null;
+      cost?: number | null;
+      shopName?: string | null;
+      notes?: string | null;
+    }>,
+    client?: any
+  ): Promise<MaintenanceRecord[]> {
+    if (records.length === 0) {
+      return [];
+    }
+
+    // Multi-value INSERT for performance (avoids N round-trips)
+    const queryClient = client || this.db;
+    const placeholders: string[] = [];
+    const values: any[] = [];
+    let paramCount = 1;
+
+    records.forEach((record) => {
+      const recordParams = [
+        record.id,
+        record.userId,
+        record.vehicleId,
+        record.category,
+        record.subtypes,
+        record.date,
+        record.odometerReading ?? null,
+        record.cost ?? null,
+        record.shopName ?? null,
+        record.notes ?? null
+      ];
+
+      const placeholder = `($${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}::text[], $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++})`;
+      placeholders.push(placeholder);
+      values.push(...recordParams);
+    });
+
+    const query = `
+      INSERT INTO maintenance_records (
+        id, user_id, vehicle_id, category, subtypes, date, odometer_reading, cost, shop_name, notes
+      )
+      VALUES ${placeholders.join(', ')}
+      RETURNING *
+    `;
+
+    const result = await queryClient.query(query, values);
+    return result.rows.map((row: any) => this.mapMaintenanceRecord(row));
+  }
+
   async deleteRecord(id: string, userId: string): Promise<void> {
     await this.db.query(
       `DELETE FROM maintenance_records WHERE id = $1 AND user_id = $2`,
@@ -336,6 +392,80 @@ export class MaintenanceRepository {
     return res.rows[0] ? this.mapMaintenanceSchedule(res.rows[0]) : null;
   }
 
+  async batchInsertSchedules(
+    schedules: Array<{
+      id: string;
+      userId: string;
+      vehicleId: string;
+      category: MaintenanceCategory;
+      subtypes: string[];
+      intervalMonths?: number | null;
+      intervalMiles?: number | null;
+      lastServiceDate?: string | null;
+      lastServiceMileage?: number | null;
+      nextDueDate?: string | null;
+      nextDueMileage?: number | null;
+      isActive: boolean;
+      emailNotifications?: boolean;
+      scheduleType?: string;
+      fixedDueDate?: string | null;
+      reminderDays1?: number | null;
+      reminderDays2?: number | null;
+      reminderDays3?: number | null;
+    }>,
+    client?: any
+  ): Promise<MaintenanceSchedule[]> {
+    if (schedules.length === 0) {
+      return [];
+    }
+
+    // Multi-value INSERT for performance (avoids N round-trips)
+    const queryClient = client || this.db;
+    const placeholders: string[] = [];
+    const values: any[] = [];
+    let paramCount = 1;
+
+    schedules.forEach((schedule) => {
+      const scheduleParams = [
+        schedule.id,
+        schedule.userId,
+        schedule.vehicleId,
+        schedule.category,
+        schedule.subtypes,
+        schedule.intervalMonths ?? null,
+        schedule.intervalMiles ?? null,
+        schedule.lastServiceDate ?? null,
+        schedule.lastServiceMileage ?? null,
+        schedule.nextDueDate ?? null,
+        schedule.nextDueMileage ?? null,
+        schedule.isActive,
+        schedule.emailNotifications ?? false,
+        schedule.scheduleType ?? 'interval',
+        schedule.fixedDueDate ?? null,
+        schedule.reminderDays1 ?? null,
+        schedule.reminderDays2 ?? null,
+        schedule.reminderDays3 ?? null
+      ];
+
+      const placeholder = `($${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}::text[], $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++})`;
+      placeholders.push(placeholder);
+      values.push(...scheduleParams);
+    });
+
+    const query = `
+      INSERT INTO maintenance_schedules (
+        id, user_id, vehicle_id, category, subtypes, interval_months, interval_miles,
+        last_service_date, last_service_mileage, next_due_date, next_due_mileage, is_active, email_notifications,
+        schedule_type, fixed_due_date, reminder_days_1, reminder_days_2, reminder_days_3
+      )
+      VALUES ${placeholders.join(', ')}
+      RETURNING *
+    `;
+
+    const result = await queryClient.query(query, values);
+    return result.rows.map((row: any) => this.mapMaintenanceSchedule(row));
+  }
+
   async deleteSchedule(id: string, userId: string): Promise<void> {
     await this.db.query(
       `DELETE FROM maintenance_schedules WHERE id = $1 AND user_id = $2`,
diff --git a/backend/src/features/vehicles/data/vehicles.repository.ts b/backend/src/features/vehicles/data/vehicles.repository.ts
index cd9311b..3f2df8a 100644
--- a/backend/src/features/vehicles/data/vehicles.repository.ts
+++ b/backend/src/features/vehicles/data/vehicles.repository.ts
@@ -164,6 +164,57 @@ export class VehiclesRepository {
     return this.mapRow(result.rows[0]);
   }
 
+  async batchInsert(
+    vehicles: Array<CreateVehicleRequest & { userId: string, make?: string, model?: string, year?: number }>,
+    client?: any
+  ): Promise<Vehicle[]> {
+    if (vehicles.length === 0) {
+      return [];
+    }
+
+    // Multi-value INSERT for performance (avoids N round-trips)
+    const queryClient = client || this.pool;
+    const placeholders: string[] = [];
+    const values: any[] = [];
+    let paramCount = 1;
+
+    vehicles.forEach((vehicle) => {
+      const vehicleParams = [
+        vehicle.userId,
+        (vehicle.vin && vehicle.vin.trim().length > 0) ? vehicle.vin.trim() : null,
+        vehicle.make,
+        vehicle.model,
+        vehicle.year,
+        vehicle.engine,
+        vehicle.transmission,
+        vehicle.trimLevel,
+        vehicle.driveType,
+        vehicle.fuelType,
+        vehicle.nickname,
+        vehicle.color,
+        vehicle.licensePlate,
+        vehicle.odometerReading || 0
+      ];
+
+      const placeholder = `($${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++})`;
+      placeholders.push(placeholder);
+      values.push(...vehicleParams);
+    });
+
+    const query = `
+      INSERT INTO vehicles (
+        user_id, vin, make, model, year,
+        engine, transmission, trim_level, drive_type, fuel_type,
+        nickname, color, license_plate, odometer_reading
+      )
+      VALUES ${placeholders.join(', ')}
+      RETURNING *
+    `;
+
+    const result = await queryClient.query(query, values);
+    return result.rows.map((row: any) => this.mapRow(row));
+  }
+
   async softDelete(id: string): Promise<boolean> {
     const query = `
       UPDATE vehicles
diff --git a/backend/src/features/vehicles/tests/integration/vehicles.integration.test.ts b/backend/src/features/vehicles/tests/integration/vehicles.integration.test.ts
index 5ef2912..ea9062b 100644
--- a/backend/src/features/vehicles/tests/integration/vehicles.integration.test.ts
+++ b/backend/src/features/vehicles/tests/integration/vehicles.integration.test.ts
@@ -12,9 +12,8 @@ import fastifyPlugin from 'fastify-plugin';
 
 // Mock auth plugin to bypass JWT validation in tests
 jest.mock('../../../../core/plugins/auth.plugin', () => {
-  const fp = require('fastify-plugin');
   return {
-    default: fp(async function(fastify: any) {
+    default: fastifyPlugin(async function(fastify: any) {
       fastify.decorate('authenticate', async function(request: any, _reply: any) {
         request.user = { sub: 'test-user-123' };
       });