"Gosh! Where have I parked my car???"
Did this happen to you and had a hard time searching for your car in a Commercial Buidling basement carpark?
Why did I specifically mention a basement carpark? Because there are already GPS products out there that allows you to locate your car in a open area carpark.
GPS will not work in an enclosed area.
How about an improvised car remote key (with a lcd display) that will store the location of your car?
But the carpark needs to enhance their system as well.
Referring to a typical shopping center carpark in Singapore, these days it has a sensor on top of each lot to show whether it is empty or not, and it "feeds" information to the various monitors on the number of available lots around the car park.
How about improvising this sensor and make it transmit the location of that lot?
Then with the improvised car remote key, while locking your car, it will receive a signal from this sensor and locks down the lot number and location into the car key, and display it on its lcd screen. This is a simple design.
More complex design may include a bigger lcd screen that will display your current location and the car's position in real-time. That way you just need to follow the signal to reach your car.
How does this idea sound? :)