A Kickstarter funded iPhone application can help anyone find his/her car without too much husle. The project raised over $40k and with this money it manufactured the USB Bluetooth devices that need to be plugged into your car for this to work.
Because the app communicates with the car via Bluetooth you don't need to manually pin the location of your car every time you leave it. The app does this for you so it can show you your car location even if you are outside the Bluetooth range.
The iPhone 4S application is every driver's dream. It shows how long you've parked your car, how far is it and shows you the way back to your car via a map. The application costs $1 on the Market and together with Bluetooth device is costs $26 but you will need to have an USB charger adapter.