Here's another option to consider for your rack: get Planet Bike's mount and drill a hole through the rack's double-bar section above the rear tire. Use an extra-long bolt to put Planet Bike's mount there.


Also, here's another backup light to consider: Trek's "Beacon" bar-end lights These take one AAA each and are visible from both the rear and the side, and since they're at the tips of the handlebar, they give you definite "width" as well. Your Trek dealer may have these in stock for you to check out. Runtime could be better, but at least they'll take a common AAA rechargeable cell.