Dave I wish I could take you for a spin around waterford in a touring prepared car, I guarantee you will never look back. Also NO NOT be afraid to get away from the mustang if you are looking into racing, I guarantee if you drive a spec miata at full speed around a road course I guarantee the experience will kick the arse out of anything you have driven on the street. Factor that by 5 if you do wheel to wheel.
That aside, the s60r is a very nice car that I think you should definitely consider as well.
The srt-8 will pretty much give you enough handling that a long as you keep it on the street, you will rarely be able to approach it's limits. It is definitely one of the be better automotive buys at the moment. 42 gets you a commodious and quite luxuriously appointed interior, navigation, and great handling power and especially braking (check out the numbers). Also consider the fact that many in the area will look negatively towards a european or japanese car.
