Interesting that my real life vehicle has TC and it activates in the rain and snow. Silly me for thinking that in a game that's touted as real driving simulator, that TC would also work in the rain. My error on that as its different with race cars.
Got to love people like you that are myopic and utterly condescending. Because something doesn't happen to you or you don't understand something, it means its non-existent or the person is lying etc. I've been given penalties doing nothing wrong driving in the rain, you are on the tarmac, not even touching curbs etc. Driving dry, touching a particular curb gives no penalty. Touch that same curb in the rain you get a penalty. I've been hit off by the AI and given 10 sec penalties a few times as well in the rain. Again, in my experience driving Le Mans circuit, the penalty system seems more hyper reactive than in dry driving.
Also the AI some how on slicks are able to get forward motion when I can't on same slicks. Its not every time but its happened often enough for me to notice it. Several cars like the Viper and the Supra will pit in during rain and still come out on slicks. Makes no sense and needs to be tweaked. Go ahead and look at a replay after the cars pit in the rain. Then look at every car and you will see some on rain tires and some still on hards/med/softs, even when there is a massive down pour.
I grind WTC 700 daily as well and this is what I've experienced over the years.