AutoTrader NZ Car Scraper - Chrome Extension

Project Overview

AutoTrader NZ Car Scraper is a powerful Chrome extension designed to automate the extraction of car listing data from AutoTrader NZ and other online car marketplaces. The extension intelligently navigates pages, extracts relevant vehicle information, detects duplicates, and stores the data locally for later export. With automated pagination and real-time monitoring, this extension streamlines the car data collection process, saving hours of manual work.

Key Features

Automated Data Extraction: Scrapes car listings intelligently using multiple selector strategies
Smart Pagination: Automatically navigates through multiple pages while maintaining data persistence
Duplicate Detection: Prevents redundancy through title matching and phone number normalization
Data Persistence: Saves all scraped data across pages and sessions using Chrome Storage API
Auto-Start Functionality: Automatically resumes scraping when navigating to new paginated pages
Real-Time Monitoring: Tracks progress and logs activity through the extension popup
Export Capabilities: Download scraped data in JSON or CSV formats for easy analysis
Multi-Selector Strategy: Robust fallback selectors to handle dynamic page structures
Load More Handling: Detects and clicks “Load More” buttons automatically to reveal additional listings
Error Recovery: Retry logic and graceful degradation ensure stable operation

Technical Stack

Extension Architecture: Chrome Manifest V3 with service worker background script
Content Scripts: JavaScript for DOM scraping and element detection
Storage API: Chrome Storage API for data persistence across pages and sessions
DOM Manipulation: querySelector strategies with fallback options for dynamic pages
Data Formats: JSON and CSV exports
Messaging API: Background-content script communication for real-time progress updates
Error Logging: Console logging with clear status and error messages

Technical Implementation

The extension uses a structured three-layer architecture:

Content Script (CarScraper Class): Performs DOM analysis, element detection, data extraction, and duplicate filtering
Background Service Worker: Manages the extension lifecycle, message routing, auto-pagination, and storage operations
Popup UI: Provides real-time monitoring, controls for starting/stopping scraping, and export options

Workflow:

User Interaction (Popup UI) → Background Service Worker → Content Script (DOM Analysis → Element Detection → Data Extraction → Duplicate Filtering) → Chrome Storage (Persistence) → Auto-Pagination → Results Export (JSON/CSV)

Business Impact

Efficiency Gains: Automates manual car data collection, saving hours of repetitive work
Data Quality: Ensures unique datasets through duplicate detection
Scalability: Handles large-scale scraping across multiple pages automatically
User Experience: Simple one-click interface with real-time feedback and progress tracking
Cost-Effective: Eliminates API costs or subscription fees
Integration Ready: Exported data is easily transferred to other systems for further analysis