I think the BEST way to classify races would be in different kinds of cars, i think 3 kinds would be best
the Imports, super cars, and generic.... imports include all the cars that can be modded at arch angels and the other mod place (thats not transfenders), like elergy, flash, sultan, etc.... super cars are the fast ones, turismo, GT, NRG, bullet, cheetah etc (but i think infurnus should be left out in this category), generic would be all the other cars, like buffalo, huntley, PCJs, basically anything thats not a import or a super car...
when selecting race, it would be say, something like /racehost xxxxxx xxx xxxx etc, then you select the track, say all around SA 1 lap, then you select car class: all, import, super sport, or generic. (all cars would include infurnues, any other will not).