I agree with Dave...wait until the break in is complete. Then do two things back to back in both cars:
- Find a good twisty road (Laureles Grade?) and drive it HARD.
- Find an empty wide area and turn off DSC..hoon it a bit.
Pick the car that you had the most fun in. If you turn around when you get out of one of the cars to look at it, that is a pretty damn good reason to keep it