Rich, I (and my brothers) were members of their "President's Club" for quite a few years and have ordered lots of stuff from them. One brother then worked for them for a few years. I don't know how new your friend is to this, but if he's close enough to one of their stores, let them do the installation. They install what they sell and do it cheaper than anywhere else I know of. And a couple of other things I liked about them was a true "satisfaction guaranteed" money back policy, and the fact that they have no objection to you going into the shop and watching their service personnel work on your equipment (unless any of their policies have changed in the last 5 years). I suppose your friend has also considered what he is going to do about tail/turn signal/brake lights on the car when he's towing it; usually simple enough but there are some alternatives, and it can be a bit complicated if you're not familiar with electrical work.
Bird