This was always our biggest worry, trailer security. We use to do car shows and sand drags, and like most people we spent an awful lot of our hard earned money on tools, cars and everything else it takes to go racing and have fun. Most people go to great lengths to plan and budget for a new car, but forget to budget for the trailer and support vehicles. These items that are often overlooked can add up to a significant amount, from as little as 10-15 thousand to as much as $100,000. 00, depending on your needs and taste. All to often you see a guy spend $40-50,000 on a project and try to transport it on a $1200 trailer, it just doesn't work. Non-days, open trailers are useless when transporting high dollar equipment. Enclosed trailers are the only way to go, they offer the security and enmity others can not. But, while offering protection from the element, on-lookers, and the casual thief, they do not posse a threat from the professional or bold thief's that lurk around hotels,race events and any other area that might bring an opportunity. This kind of predator knows what jewels awaits inside these huge enclosed trailers and they have the means and balls to steel the contents or whole trailer (many simple break into the tow vehicle and drive off with the whole thing).
Anyone that has ever been in this situation, knows the concerns and dilemmas of the problem. You can insure the trailer but know one will insure the contents. There are a few companies that will insure the race or show vehicle, but extremely high premiums cause most to fore go this option. Rates usually run 1/4 to 1/3 the value of the insured, which would have you paying $25,000 for a $100,000 vehicle, way more then most could afford. So you settle for insurance on the trailer and the truck to tow it and hope for the best. This leaves you with a $75-100,000. 00 car, 10-$15,000. 00 in tools and another 10-$15,000. 00 in part and what have you, all UN-insured and waiting to be stolen. What can you do? Well to start with, you drive very carefully, avoid bad parts of town, and always fill-up in well lite well used stations. I like to pay at the pump, it is fast and allows you to get back on the road with-out drawing attention to yourself, and with-out going inside and and flashing any cash.
When staying at hotels, some have CCTV of the parking lots, try to find these. Also, get a room that allows full view of the trailer, and is close enough for the alarm remote you should have installed in the trailer. The exterior padlocks should be of the highest quality you can find, and they should be on every place made for the locks. These means every door, entrance or ramp, the trailers hitch lock and the trucks ball mount lock. Go to a lock specialist and get the locks all keyed alike, it makes life much easier. I also put a chain(use a high strength chain with a protective cover) through the wheels to lock them from turning, and use locks on the safety chains that go from trailer to truck. The ideal is to make it as hard as possible for anyone to steel. The trailer should have it's own alarm system as well as the truck, and the louder the alarm the better. I like to use both sirens and lights to draw attention to the trailer. You can mount revolving lights on top the trailer like with a 15" or 22" Mini bar or my favorite the more subtle undercover strobe lights in the tail lights, the main focus is to draw attention to the trailer. Of-coarse the alarm must have it's own power supply, you can use the trucks system to re-charge the alarm batteries, but they must be self contained and in the protected trailer to be effective.
Their is no system that is full-proof, but with enough foresight and good old common sense, you can dramatically reduce your chances of theft. Good luck and keep the eyes wide open.
Attention: TDR Forum Junkies 
) Then, three words... wiffle. ball. bat. Do you know how much frustration you could vent, non lethally, with a wiffle ball bat?? Think of the welts. :-laf "TALK! You blueberry bstrd!" Whack! "Where's my toos?!" 
:-laf :-laf
