the Porsche? -possible spoiler.

Well I personally think it's because of the different types of lies like the chicks digging him and the father and mother doing stuff, all of a sudden chicks don't like him anymore and father and mother stop doing the stuff they were doing but there was still evidence of all the stuff they did so for instance the car can't really just vanish on it's own you know similarly I would think anything physical that got from the lies would remain his unless some one took them from him, any way yeah hope that helps