I have installed mine, but haven't finished the AC hoses yet. Had the heater up and running at end of winter this year, and it was fantastic heat for my 300 tdi 110. Even if it was the same capacity, the fact that it pulls air from the cabin instead of external means it has a compounding effect. Expect the same with AC. And I don't give up any front knee space for an under dash unit. no regrets so far.