Depends on what you have room for. If you are running a bunk over the cab, then you'll mostly likely run it out the drivers side on ground level. If you are running a condo version which was designed for a stack or you can make room for a stack and that is what you like run it up. I have no problems with the ground level exhaust, only time I can hear is under a over pass or along side a concrete barrier.
2003 28' Show Hauler Motorhome on a 1995 FLD 120 www.showhauler.com