as time passes lobbies are going to be basically freed from excited one-timers
then a quick look at the drivers levels in a lobby will give you a pretty good idea of what that lobby would be.
up till last month I'd still regularly play F5 online. game would match me in lobbies with players with level in the thousands.
bumping car game as you understand was never a thing on those lobbies, and if accidents happened the whole race would often come to a temporary crawl because "no, you go ahead" "no you!" kind of behaviours
once every while I would still get matched with a rail-rider or a bumper, but he would very soon understand that this is not a lobby for him and quit.
(also rail-riding is ..taken care of I think? I noticed that if you go scratching your side to a rail in alps, car will greatly loose speed after the first few meters)
as a last resort, you can ALWAYS open up the players gamercard (press A on his name in lobby), and a) make complaint and/or b) block
system works like a miracle: 10 complaints (which in a 24 player lobby are very easy to obtain) and next time the ...player tries matchmaking he will get my @@ ,
and use of block makes 100% certain that Forza will never again match you in a lobby with a player you blocked.
I suggest you dont use the "last resort" for excited players (vote to kick in-lobby works well if words dont go across),
reserve it only for assholes.
example: we filed 15 complaints on a dude on our lobby that insisted for the third time on picking that armored FF truck just to stay a lap behind and cause great accidents as people lapped him.
thats an asshole definition, deserving to have his matchmaking ruined