I got a fantastic tip from "Mr. rF2" himself. If you are interested in offline rain races, you have to save the asphalt track when it is wet enough (e.g. spa_wet_grip) and then load this file shortly before the start. It works! Finally rain races in offline mode. Thank you very much Mr. Offermans!✌️
what? You mean setting the weather to light rain doesn't do the same for offline? Or injecting wet weather with the realtime weather plugin?
Hmm yeah there's some miscommunication there in the OP, i think what he's referring too is if you ONLY select a Race (no practice or qualifying) you can load the pre saved Wet Real Road so the track is fully wet from the very start.