Anyone have the rear bumper cover from Mazdatrix? I do and the openings measure 4inches .......So can i put 4 inch tips in there or should i go 3.5? What will happen if I run 4" tips and they touch the fiberglass?

 

is this thing on?

 

Yea, it's on! My thoughts-If you put a 4" tip inside the 4" opening of fiberglass, you probably will have 4.5" opening after a short period of time. Take a piece of fiberglass on place it on the underside of the exhaust and see the effect. I would stay with the 3.5". A little clearance is necessary, heat and pipe movement.

 

thanks that's what i was thinking.....I appreciate your input...