It may have been stimulus-that-could-pass and and a justifiable could pass extra boost to the ailing domestic auto industry,
but of course cash for clunkers was a super expensive program for meager results. The government spent a bunch of money to encourage people to do things that most were going to do anyway, either now or soon. Any incentive program which mostly compensates people for something they were going to do anyway is pretty low bang for the buck.
