Wireless Magnetic Car GPS Tracker

I want a self-contained GPS tracker that snaps magnetically onto a car’s chassis and keeps reporting its real-time location without relying on any phone app or cloud dashboard. All positioning data should come straight from the device itself—either displayed on a small built-in screen, spoken through a buzzer/voice prompt, or transmitted by SMS/GPRS so I can query its whereabouts on demand.

Key points I need covered:
• Stand-alone operation – no external app or web portal required
• Strong magnetic mount suitable for everyday cars, remaining secure at highway speeds and through rain, heat, and light off-road vibration
• Accurate GPS/GLONASS reception with frequent, user-configurable update intervals
• Long-life rechargeable or replaceable battery, plus a low-power sleep mode that still allows instant wake-up for live tracking
• Simple user interaction: one-button arming, LED/buzzer status feedback, and an easy way to send or display its current coordinates

Deliverables
1. Full hardware design (schematic, PCB files, BOM) and enclosure model showing the integrated magnet system
2. Firmware source code that handles GPS acquisition, power management, and the chosen communication method (e.g., GSM SMS or GPRS)
3. Assembly and usage guide so I can reproduce, install, and test the device on my own vehicles
4. A brief field-test report proving reliable tracking accuracy and magnetic retention under normal driving conditions

If you have experience with low-power embedded design, GNSS modules, and ruggedized enclosures, I’d like to see how you can turn this concept into a ready-to-deploy tracker.