One other tip. I swapped out the 2x4's on my tire rack for square tubing with pins on the end. That way the tire rack is easy to take down when you're at the track. I got tired of having to duck everytime I walked from the back of the trailer to the tool boxes in the front. E-track is awesome though. I use it for the car tie downs as well since it's so hard to get under my car.
-Duncan