I run stretch H20's (275/35/17 on 17x11's)...it's disturbing how good they are. I watched John V (DSP BMW) out pace STR at Toledo last year (STR ran in the bone dry) in 4" of standing water on new H20's. Sadly for us first drivers, the rain hit as we were pulling into action. I don't change a thing on the car from wet to dry.
A6's were all kinds of fun at Toledo last year: