The rain in pCars is pretty awesome. Much better than rF2. I have been messing around with random weather and retro cars against AI. I like that the rain collects on the windscreen, the windshield wiper work and the spray too. I posted this in a thread in the pCars forum but so far there aren't any responses.
I don't feel that AC reflects the essence of what this league was supposed to represent when we began. We started with random weather, lots of damage and varied length races. With AC we've dumbed it down and now we have no one on the grid AND lost how we began our racing. rF2 never really panned out because the rain in rF2 is seriously flawed and at this late stage there's still no rain on the windshield and the rain grip is VERY buggy. AC is an arcade driving sim with no weather but great dry physics and terribly designed for racing. So far pCars is by far the best sim for non-ideal weather.