Yeah yeah I know, it's been asked many times, but it was never answered properly??? I tried random but one smashed into the other, the other tried to self destruct its engine and the other smashed into a guardrail while I was at the starting line. I saw a tutorial on the pathfinding for the NPC's for them to follow but it crashed my game, and currently I'm pissed off...
Not 100% sure, but I think real clean racing with AI isn't possible YET. But I saw TDev working on AI, so maybe in the near future, I hope. there may be some difficult way to make it somewhat possible tho.