I was thinking the other day about this. They have cars that can park themselves already. I think Audi has been advertising them. They obviously use some sort o

I was thinking the other day about this. They have cars that can park themselves already. I think Audi has been advertising them. They obviously use some sort of sensor to detect empty parking spaces. What would be brilliant is if they did two things: 1) Used GPS coordinates to figure out if you are in a high-demand area for parking and, if so: 2) Passively scan for parking spots as you drive by, then upload them to the cloud. You don't actually have to be looking for a parking spot -- but your driving by an empty one could help someone else. A more YC-focused idea is to design a small device that does exactly that for any car and is as simple as dropping something onto your antenna or sticking it on a passenger-side window.