These are the reasons why I hate trying to find lobbies on GT6, 99% of the lobbies are dirty lobbies (it says so on the title). I mean what are they doing on GT6? That's why I don't play with other people that often, each time I get into a lobby someone in there is going to play dirty and crash people at some point.
To me Dirty isn't a form of racing at all, smashing cars isn't racing it doesn't require any skills, you just have to floor it until the next corner and crash whoever is in front of you. I'm not going to lie, I've played some dirty "races" with a couple of friends just to laugh but that only happens after we've made a fair amount of clean races before, it allows to remove the competition spirit of the lobby before we all leave the room, it's fun to leave with a laugh rather than I didn't win, or I should've won, etc... it kind of erase the memory of the previous races.
Now NASCAR, I'm having a really hard time finding Clean NASCAR lobbies, mostly because when I do I get kicked before I even go on track, I can't blame the owners of the lobbies since everytime I managed to get in a lobby the people that are not American or Canadian tend to crash people because they can't hold their line, but sometimes Americans and Canadians are going to bully us on track and squeeze us under the yellow line, if we don't back down it's going to be a crash and another reason to kick us and since I don't like to be bullied on track, you know where we usually end up... yup, were it says Daytona on right side of the track. I've had a lot of great NASCAR races with Americans though, they were nice enough to treat us like we weren't from another country.
But to be fair NASCAR is their sport, so they usually assume that we don't know much about it which may or may not be true, just like europeans are going to think as road racing as their own (even though the US also have road racing). But we have a certain mentality over how to race each other that the US doesn't have (we have a softer kind of racing and it's boring) and Amerians have their own mentality over how to race each other which is a lot tougher but more exiting, that's why europeans might kick american players for the way they race when they thought they were clean (and they were just not the european version of clean racing) and that's why americans will think we're "blocking" when we're covering the inside when it's just racing the european way.
Anyway, my point was that DIRTY shouldn't be part of any proper racing games, if you want to play dirty go play GTA V and play races online.