I started out
hating going on track in the rain (first time on rain soaked track ever, with no preparation, in a DE, resulted in a spin in the very first corner at Sonoma, only going 15MPH, which left me fearful of a wet track), but once I got a chance to do it with full tread tires, I got pretty comfortable.
The video below is my in-car from the final race of the season a couple of weeks ago at Buttonwillow with PCA Club Racing. It rained hard in the morning and again as the race started. A couple of people gambled on dry tires and lost out. I took P1 in Spec Boxster and P3 overall. Besides the lack of traction (which I never wanted to really test the limits of) the worst part was visibility. There's no HVAC (defrost or fan) in a race car, so fogging is a big issue, and when a car is in front the spray reduces visibility to almost nothing! The spray makes you want to back off until you can go off-line, and when you get by it's like taking off a blindfold, allowing you to see the edges of the track, and where the next corner is!
[video]https://youtu.be/IbxKKUsW7cw[/video]