I guess the real thing behind all this is, do you think the game itself ought to adjudicate contact better? It's all well and good to bitch about less principled drivers, but all they are doing is exploiting the game mechanics. Even real racing IRL, there are Stewards. Drivers aren't expected to police themselves, as they can rarely see the big picture from the cockpit. Fail to enforce those rules will ALWAYS end up in pretty much the same behavior even on real tracks.
So, what could the game do? First of all, I'm assuming that full damage and penalties are on, and Boost is off. If you are racing in lobbies without those, you are setting yourself up for ramming...
The game already TRIES to penalize flagrant ramming, and does a lot of weird stuff making you go 'transparent' when trying to squeeze into to small a space (and that's too 'arcade' for me!) with other cars around, but could it do a better job? Could the game keep track of how many side to side racing 'moves' you make, and penalize you for blocking? Most racing, you only are allowed one or two of those. Mind you, the exaggeration of drafting power needs to be diminished a bit, too. The trailing car seems to have a greater edge than IRL, at the moment.
Personally, I'd like to see game ending damage (but not visually only, like now). If the consequences of contact were more severe, contact would be a FAR less likely solution for those defending, or aggressively attacking position. To be honest, it is what keeps real racing at least from devolving into demolition derby..! At least half the time, shunt someone out, and YOU suffer consequences, too.
Maybe the game needs one more damage option... 'Terminal'
Then the 'clean' guys would have somewhere that no basher would ever DARE show his face in!