After studying all the various different install instructions posted on AW, I decided to take the easy way out and do Jonah's velcro install on my 02 S4. Luckily I already had a roll of industrial-strength velcro, that I bought for earthquake-proofing some shelves.

I cut the strips for the wide shelf on the RH side of the changer compartment, and decided to cut a super-thin strip for the little thin shelf on the LH side. In retrospect, this did almost nothing, because the angled edges of the phatbox means that the velcro barely touches on there. If I had to do it again, I would put a strip of velcro on the vertical edge for the left side, instead.

Couple of tips for anyone else considering doing this. Put the hook-side of the velcro onto the changer compartment, and the fluffy-side on the phatbox. The hook-side sticks to the trunk liner interior, which can be annoying. Also, to make final positioning easier, put a thin sheet of paper on top of the velcro in the changer compartment, slide the phatbox in on top, get the positioning exactly where you want it, then hold the phatbox in place with one hand and pull the paper out with the other. This stops the velcro attaching too early. Once that stuff is stuck, you're not getting the phatbox out again without a major struggle!

One side note, my compartment cover for the cd changer/toolbox keeps coming off while I'm driving, and the toolbox flies out. Anybody got a quick fix for that? I keep having to jam heavy objects up against the door to keep it in place. Now I've got the phatbox installed I'm worried about the toolbox hitting the phatbox cartridge on its way out.