I've heard good things about Toyo RA-1's for autocrossing, etc. however, they aren't made in the stock tires sizes for a 98 M3. (Front 225/45R17, Rear 245/40R17) What size should I use? http://www.toyo.com/tires/tire_lines/high_perf/specs/ra1.html lists the available sizes, and there's only one for 17", 235/45ZR17. 4 - 16" sizes are listed, are 16" better? Should I go for 4 - 16" wheels of the same size, or should I try for a stager combination?