Why mount it on a bumper?? The ARB compressor is freaking tiny. Here's a pic of my install (please pay no attention to the dirt...):



Here's what's involved... Rotate the cruise control unit, and slide down the fender slightly. Install bumper on top of fender. no special brackets involved. Time to do it: 'Bout 20 minutes, tops.

But on another note... DON'T BUY THE ARB AIR COMPRESSOR!!!!! It's junk. I've had nothing but problems with 2 of them, so far. The first one was non-running when first purchased. Took it apart, and found that the internal power wires weren't soddered, and were disconnected. Got an immediate replacement. Second one just crapped out on me for the final time this past weekend. It's just over a year old. Guess what...out of warranty. Save yourself the time and trouble, and buy a reputable air compressor. The ARB just plain doesn't cut it. (And if you actually plan on airing up tires with it, please remember to bring a chair, umbrella, and a jug of lemonade, because you will be sitting there a long, long, long time, waiting for it to fill a tire)