Rival category for stock cars

As we now have to mindlessly grind our cars to level 50 for various reasons, why not ad a special “rival” for each car as it is purchased, you can race it only in its stock form, if a single part is modified you cant compete anymore. This way we can have a stock leaderboard.
I understand that saving this much data can be a problem, so why not make it without replay and/or for friends only at least