Everytime I wash my car, it stutters at 2500rpm exactly. Let the car sit for a while and the problem dissapears. This is my second Z. Both with the same problem. Any thoughts?

 

cold air intake? if so, you're getting it wet.

 

+1 How's your hood seal looking?

 

I get the same thing if i wash my car and too much water sprays under neath it.Its because of my cold air intake and im getting it wet just like 350Zenophile had mentioned.I took black duck tape and covered all the open slots in the front driver side wheel well to prevent water from getting in.If it was raining hard out my car would sputter alittle while driving untill i covered the slots.Give it a shot.No one will ever even notice the tape and you really dont want water getting into your engine.