I think the fairest way to do this would be to have to post your vehicle config for each run (by opening the vehicle config screen at the start/end of the run), so that the playing field stays level, and skill remains at the top, compared to set-up knowledge or tuning. I do think that setup innovations are part of the run, but they should be shared once discovered. This would also allow to check for modded parts on the car, which could be hard to check for otherwise (ex : SUPERNOS, ExtraGrip tires....).