Advertised rules do not work in DTM 2015. I have mandatory pitstop on, but AI does not pit. I have cutting track penalty on, but if I cut, I get no penalty. Finally, the game crashes before the race is over. It's a letdown. I have all Raceroom DLC and I'm going to support Sector3 in the future too, but please do not release faulty stuff like this.
Only the second race of the weekend features a mandatory pit stop, you have to skip the first race of the weekend if you want to race with a mandatory pit stop. Cutting track penalties work, and you can upload your crash dumps in the support section.