The results were shocking. You might be surprised to learn that when gas prices go up, people shop for more efficient cars. Actually the relationship is not quite that simple. With prices below $2.80 a gallon the relationship is fairly linear. Above that price point, things change much more aggressively. The consideration of vehicles like hybrids goes up dramatically while mid-sized SUVs plummets. This would seem to correlate well with the declining sales of vehicles like the Ford Explorer and Chevy Trailblazer. There's nothing here that anyone should find to terribly shocking, but it's interesting nonetheless.
[Source: AutoObserver, thanks to Srini for the tip]