I don't agree. Short term spikes in demand cause more volatile price fluctuations and overshooting. Moreover, artificial increasing demand in the short run does nothing for long term growth and can actually hinder it. It's very much like that gas tax holiday crap the candidates were talking about a year ago.
But the real issue here is this: if you have a car that works, you should not be going into debt to buy another one. That's what this whole program was about -- keeping the debt bubble growing.