the requirement of a trailor and then having to swap tires at the track is a PITA with Florida heat, no way!!!!
You don't need a trailer, really. I ran R-comps with an Escort, a B15 Sentra, and an EP3 Civic hatch and they could all handle an extra set of tires without a trailer. Especially with the hatch and the back seat down, it wouldn't be a problem in the MS3.
As for swapping tires - amen, brother! That's why I'm back on street tires this year. (2thumbs)