I am thinking of installing cut outs and assume they go just before the muffler ? If so, what is the chance of exhaust fumes coming into the car when the cut outs are open and the car is idling ?
Thanks

 

Well unless you have true dual exhaust you will only need 1 cutout. As for the fumes i haven't smelt any fumes coming into the car. I don't think you would get any fumes anyways as long as there is wind blowing.

 

Not much people complain of fumes. Most people mount it towards the rear of the car right before the exhaust turn up at the rear end.