HDDP I really appreciate your information. It is very advantageous for me to stay in the D stock class as the Crossfire competes very well. There is a handicapping system for Solo called PAX that corrects your times based on the car class you are driving. It is supposed to show who is the "best autocrosser" regardless of your car class. In the first race this year I placed 3rd in the PAX out of 39 drivers being beaten by a Subaru WRX STI and a Miata with DOT R compounds. With the typical 2 second gain on a 60 second course from R compound tires I would have won PAX easily. Being in Montana and the NorPac Division (Wa, Or, Mt, ID, Alaska, Northern Ca, NV) there are not many cars in my class so my goal is to win the PAX each race. Nationally BMW 3 series cars dominate the class, but I think that the Crossfire competes very well if it has R compound tires. If I went to D stock prepared with all 18 inch rims then my PAX correction would be much higher and I would essentially finish in the same PAX standing even with a 2 second better overall time. The good thing about D stock prepared is that it allows for many more other modifications such as ECU upgrades, more intake and exhaust upgrades, etc... All I have now are K&N filters and a Flowmaster muffler with the stock tips welded back on.