I think this would be awesome! I just gave it my 3 votes and also left a comment about why I think it would make the time trials better. I hope they implement this idea! Even if they aren't sure about it, at the very least they could just add that as a secondary TT in addition to the regular current version where you can use your own car and your own tune/setup. Like, for example the way how they have two TT for each two week TT event, instead of having them both be the way they currently are of people using any of a wide variety of cars and infinite variety of tunes/setups, they could just have 1 of the two TT's be that way and the other be this new version where they supply a specific car and tune/setup that is unchangeable, that way people can choose, depending which version of TT competition they prefer, best of both worlds (although personally at that point I would just ignore the old-version TT's and stictly do this new version if that existed, but that's just my personal taste, but, that way at least the people who fear change and don't want it to be a no-excuses scenario where it's strictly about who is the best driver since no other factors when everyone racing identical cars, those guys could still go and have their old version TT to go to if they wanted, and then the cool people could all have fun in the new version, if like, both versions existed simultaneously, by having 1 of the 2 TT's be formatted the new style and 1 of the 2 TT's being formatted the old style). This would be a good solution!
edit: Whoa that was weird lol, I wrote this post before I saw your post. Seems like we have similar thought processes about this. I like the idea about having a comparison tool to see how you fare against those in the same car/setup as you tho. Although if they did it in that way then they'd have to vastly limit tuning options, since otherwise since there's like 109,230,350,503,358,928,319,284,742 different possible tuning/setup combinations, there would practically never be two people with identical cars/setup to compare one's self to. So, in theory probly just a straight up 1 old school & 1 new school TT with one of the current style (old school) and one of the new everyone-has-identical-car&setup style (new school) would be the best possible solution, so that people could do the TT in either format as they wished so that everyone would be happy