In no particular order:
- If they do rain, it shouldn't be half measures. I'm ok if it isn't available at launch but when it's in, it should be done right. Water pooling, rubber cleaning, track temp drops, humidity, air temp, wind/rain direction, rooster tails, dry/wet lines, etc. IMO, something like pCARS 1 or GT5/6 rain isn't really worth it. Test it in an alpha/beta and then release in full when it's ready.
- Day/night seems simple enough with the right game engine. I do think GT Sport gets the graphical feel of night racing better than other sims ATM, especially from replay. Other than making sure the graphical representation is good, just giving us pCARS 2 like time options is all I have left for this.
- Game wide BOP. GT Sport again gets this right. I should be able to quick match into an online GT3 and not have to worry about X car being 20% faster than Y car. This is pretty straight forward. Host should have detailed control over this as well and host set option should be clear before joining.
- Driver rating. This is something they are working on. IMO GT Sport is a good point just short of iRacing, which is too in depth for many people. How to "do this right" is pretty much known at this point so not much to add.
- "Performance tuning/parts". This is something that only Forza seems to care about and IMO was one of my favorite parts of old GT games. IMO given AC's mod community basically does this already, it just makes sense to have this built into the game. Basic engine mods (intake, induction, exhaust), drivetrain (transmission, driveshaft, clutch, dif), suspension (springs, shocks/dampeners, roll/sway bars), brakes (rotors, calipers, pads), wheels (tire, rims, O2/N2), and aero (front aero, rear aero, under aero). The chances for this are low, but I'd like to see it. This may only make sense on certain street cars (Sport, JDM, Muscle, etc).
- Full race/grid customization. Basically, quick and easy multiclass racing. LMP1 cars XYZ start at the front, GT3 behind, those groups randomized, quick race go. Then be able to set class specific BOP regulations, in game, for online races.
- Actually fast AI. So far rFactor 2 seems to be the only game that has naturally difficult AI. It's pretty jarring when the AI is really fast in all but one corner on a track. Give the AI >100% grip if need be, just keep them consistent through a lap. I don't expect miracles when it comes to dealing with traffic. Google and Uber haven't even figured that out.