When creating a Race, you have the possibility to disable certain cars for people to choose from if they desire to race a stock vehicle.
However, said list is huge. Take the Sports class for example: 35 vehicles. You can't even scroll all the way through the list before the timer runs out. To solve this, I've made myself a list I use on all my stunt/race/misc tracks.
The vehicles you see here are the ones I've allowed.
MCEC GT3 2nd Place, Rally Raid Season Two Champion, OHM Round 8 Winner, Sports Showdown, Halloween Sports Showdown Winner, OHM LS24h Winner, Sedans Master Class Winner, Alamo Sea 24h Festival Winner. Other Things, let's see how how long I can make this signature. Are you reading this? What's wrong with you? You're reading some Canadian Scumbag's thingy. Bacon. Maple Syrup.