Pilot, +1 on your mud flaps, but I agree with Dave on the blow out protection.
A couple of years ago, I was using my utility trailer to take a load of construction refuse to the dump. The trailer has eighth inch steel wheel wells, but when a tire blew on the freeway at 55 MPH, the tire bent the steel wheel well and pulled it inward, until it was only three inches from the rim. Needless to say, I couldn't mount the spare until I bent the wheel well out of the way (15minutes of 12 pound sledge hammer work).
So make sure that you always carry the tools to remove your mud flaps, just in case.
