I have mounted mine on the side near the back door,on one of the dubious estates I work on I even locked the van up for 10 mins and ran it,just made sure I opened all doors while I packed away to ventilate the back-I know Peter sells a flue but not sure how much for,there are already pics on the forum as I have seen them so just put fogwash or aquatic pics into the sites search engine and flick thru the posts,it is a great piece of kit but will show up the weaknesses in your plumbing,if you can get a brass hozelock screw on connector for the water out as this will be one of the 1st weaknesses exposed and there are 2settings on it-winter and summer, if you put on the winter setting keep the gas on low so you don't overheat everything as these things can run really hot, hope this helps.
Graham