The owner of the mufler shop I have all my work done suggested I run the tail pipe out the driver side behind the rear tire. This would eleviate any chance of exhaust fumes entering the cockpit. He also suggest I go with a 2 and 1/4'' pipe for back pressure and low end torq. I have noticed every aftermarket exhaust on this forum went straight out the back, with or without a turn-down. not sure of the pipe diameter? Besides the asthetics is there a reason for this? Any comments would be appriciated...Thanks

 

Some of the exhaust I have seen have the tail pipe up under the back of the jeep and I think that is a bad Idea. It would be hard to keep fumes out of the cab and I would worry about CO on slow trail rides or sitting at a long light or train stop.
Out the side would be fine as long as it looks good. Or make sure your pipe sticks out past your bumper a little.

 

I've had side pipes on all of my previous vehicles in front of the rear tire and it not only sounds great in this location but gives you more power, better looks and have never had any problems with fumes.