I'm pretty sure this has been bought of before BUT, think about it...with GP bikes and WRS.. the tracks you can get for them...They are massive, why not have a super-kart body kit? like you can get the CRG up to 200kph in a slipstream, it would just be awesome to have that. There doesn't have to be a wing setting for down-force, and I'm guessing now people reading this are thinking "whats the point in having the super-kart bodywork with no wing settings" , its a good point but I'm sure people who just want to have fun really do not care about those kind of things :) it would make it more fun, instead of always driving with the CRG, Tony kart and Birel bodywork all the time, you can drive something that looks totally different :)
People are going to be able to model bodywork for themselves soon, so the last kart is probably going to be the mini kart Piboso is currently making. After that people are going to be able to make any bodywork they want so it's worth waiting till that feature comes out and then either learning to make it yourself, or find someone else who would like it to make it.