Its Your vehicle do it how you want..........Speaking from experience, Ive had several walls....They are different, unique, Impressive, very loud.....What I disliked about them was I had to stick my head out of the window to back out of my driveway. If I went to a footbakl game and trying to back out when everyone is leaving is a pain in the arse, My buddy would get out of the vehicle and tell me when it was clear to back out....And I got alot of BS from the cops Some said it was illegal because I would not be able to see out of back window or hear if an emergency vehicle was coming up behind me, Also the cop could not see in the vehicle wich put Us both at danger.This was about 12 years agoAnd all the vehicles I had walls in were daily drivers/competition