Most race cars are not street legal, but even if they are, it's still usually a good idea to tow them anyways. The odds of your Chumpcar being in any condition to drive home after 14+ hours of racing are slim to none. An enclosed trailer also doubles as a convenient place to store your car, spare parts, spare wheels, and fuel jugs. This makes a trailer almost a necessity for any race team.
There are, of course, a lot a factors to take into consideration when buying a trailer. Length, weight, capacity, tow vehicle, etc. But I've bought exactly one trailer, so I'll just tell you my experiences with that one. It's a 24 foot Haulmark Elite II built in 1995. It was used for landscaping for the first decade of it's life, and transporting cars for a collector/mechanic for the second decade. The first thing I can tell you right off the bat is that my Tacoma does not like it.
With air bags and a weight distributing hitch, my truck will tow the trailer loaded, but it's pushing the limits of the brakes, and it really needs more power. Luckily I have friends with bigger trucks, and they're usually willing to tow to the farther races.
The first thing we decided we needed to do with our trailer was add storage for spare wheels/tires, and a rack on the tongue for fuel jugs. The tire rack was accomplished entirely with 2x4s, and the fuel jug rack is entirely angle iron and some sections of pipe used to lock them in place.
You can see we also added a full sized battery/box, because we knew we'd be adding a lot of lights later on.
Next, we decided that we needed some better interior lights, and some stupid-bright reverse/work lights. All of them are LED, so they're bright, will last a long time, and don't use much power.
You can't really see them, but these are two 12" LED light bars wired in to the reverse lights, and on a separate switch to use them as work lights.
There were only two small light fixtures in the trailer originally (excluding the 110v fluorescent light). We replaced the bulbs in those with LEDs, and added 4 LED light strips.
One of the original reasons we bought the trailer was that we could sleep in it at the track. Hotel rates add up, and that's money that could be spent on tires or fuel. You could easily just put air mattresses or cots on the floor, but we wanted beds off the floor that could be folded out of the way. We also wanted them to latch in high enough to clear the car if needed, or at a lower/more comfortable setting. We accomplished this with some hefty angle iron as uprights, and some lighter angle iron bed frames. Chains support most of the weight. The uprights are attached to the trailer's studs with my newest love, riv-nuts.
Folded out in the low position. The hinge is used to lock it while folded up, which was almost a good idea.
Bads actually being used for the first time. Those are all air mattresses, but we designed them to leave enough space for foam mattresses to stay on them even when folded up.
After our second race using the trailer, we discovered what our first project should have been. Instead of adding storage, we should have been doing routine maintenance. The person we bought the trailer from claimed that he had recently replaced the axles. Oddly enough, someone selling a used item was not completely honest about the condition of said item. In retrospect, the first thing we should have done was pull apart the hubs and check the bearings. Bearings, bulbs, and tires are the main wear items you have to worry about on a trailer. We replaced two tires and a few bulbs. Never even greased the bearings.
So as it turns out, one axle had been replaced. In 2005. The other is original from 1995. Not sure when any of the bearings were last greased, but I'm guessing not recently. With one melted spindle, we needed to replace at least one axle, but seeing as how we were pushing the weight limit on two axles, we decided to add a third. So two new axles and a complete rebuild on the one original axle.
Brackets are pretty simple angle iron (left over from the bed uprights, actually) with two holes and a square notch.
After lots of planning, drawing, arguing, planning, drinking, and more arguing, we gave up and went to town with a sawzall and grinder.
The inner fender wells were stretched too, but they're too ugly to show off. Or at least too ugly to bother taking pictures off, anyway. The brakes are electric, so the new axle was just wired in parallel to the existing brake wiring. If the middle axle looks like it's sitting higher than the other two, that's because it is. The middle axle is the original, so it's a bit more worn out. Loaded, they all sit even, so the middle axle acts as a sort of overload axle. At least that's what we're telling ourselves until we get around to ordering a third new axle. We've towed the trailer a couple thousand miles since then, and it tows great. The third axle drops the tongue weight considerably, although it does drag the tires around a bit in tight turns.
The axle upgrade was the last major project we've done to our trailer, but we've slowly been adding more storage to it. We're hoping to permanently mount an A/C unit somewhere, along with a mini-fridge/microwave next. Even with all of the headaches, this trailer has still been worth it. I highly recommend an enclosed trailer if you're going to race. Just remember to grease your wheel bearings.