anything that's a good deal is gone almost right away
I lost out on like a dozen cars before I bought my last one. And that was only because I saw the ad get listed in the previous 5 minutes, and went right away to test drive it.
As far as feedback, 1 bug - when you scroll through the makes, it keeps hiding. Especially annoying if it's a brand at the bottom of the list(i.e. Mercedes).
Feature wise, the map of the car's location isn't that useful, much better would be to just list how many miles away the person is...and maybe even estimate the time to get there.(i.e. I remember thinking oh 30 miles, not that bad...then you spend 45 minutes driving to and from there, and pretty much your entire day is gone, just to see one car)