Another output from the exhausts is heat, it doesn't sound important but it is for the simulation aspect. Heat blur is basically heat that is pushed out from the engine. Heat blur if it comes in, should move "freely" not in a fixed pattern. I'd be nice touch of realism believe me. I'd be nice to make this behave according to your power output, i.e more/less heat will be seen (not very obvious) coming out based on how much power the engine is operating at
How about bugs -- no, not software bugs, I mean insects. The entire TSW world lacks them. Just think of it: a wasp in the cab -- now, there's a driving challenge for you! And, best of all, what better target for nay-sayers than TSW full of bugs? [I rarely use emojis, but don't want any crawlers to take this post seriously.]