Since you already talked with me about this, I guess I can explain better what you're asking here.
Basically, Ender is asking for a main TS's ranking to be based on a frequently used cars. He's speaking about Hot Lap (wanking) based Ranking.
Sadly, there are no good chance for that to be implemented, at least not by a TS's players who are able to do it. For example, Tijny is probably already stopped reading this post when he saw wanking + ranking as a combination. For some weird reason, hard core players just gave up from those kind of competitions, even they're the coolest.
I spent tons of hours playing for the old ranking and that was actually the thing that kept me here for so many years. Unluckily, the new players will not feel like the game or anyone else care about their skill. Community is sending the only one message currently: Well, you downloaded the game. If you like the punabal, play it - if you don't, who cares.
Anyway, it's not just about to replace the cars. I'm sure a lot of people like the default ones. There is just no nicely organized ranking for them.