FLORIDA DMV SPECIAL CONSTRUCTION
Special construction is a process offered by some states to issue a vehicle number under certain unique circumstances and/or to unique vehicles that do not fit into a federally-recognized vehicle type. Generally, it is used for home-made vehicles whether the are kits, re-builds, or assembled from parts (ASPT).
Special construction processes are generally a pain-in-the-neck. You usually need to fill out lots of forms, submit receipts for all parts of the vehicle and undergo an inspection. Special-construction-issued vehicle numbers are usually short numbers -- 8 to 14 digits rather than 17 digits. Special construction vehicles have many drawbacks and as a result they are generally of relatively low market value. Vehicles with special construction titles can be difficult or impossible to transfer, insure, finance or take across most international borders.
Motorcycles, trailers and LSVs can and should be built under federal license with a 17 digit manufacturer VIN number. The one-time cost of this life-time license will add more value to even one vehicle than the cost of the license. If you ever have any ideas about building and selling even one motorcycle (chopper, trike, etc.), trailer or LSV, than you really should get licensed
With all of that said, special construction is sometimes the way to go. Perhaps you just have one vehicle that you are ever going to make in your life or you are building a vehicle(s) that can't be reasonably build under the federal vehicle manufacturer license -- e.g. street rods / hot rods, sand rails, flying cars, amphibious cars, hovercraft, etc. or you have a special circumstance vehicle -- e.g. no title, never titled, etc.
Below here are the forms and basic info paperwork for the Florida DMV, District 2 (Ocala) Special Construction Process in order to give you some idea about special construction processes in general as well as the specifics in Florida, information requirements, forms, etc. Florida is a fairly open-minded state when it comes to special construction. Although FLorida provides you with a good deal of red tape, they do make allowances for a wide variety of vehicles and special circumstances.
These forms might change over time so check with you DMV, etc for up-to-date info and if you are in another state you will just need to go to your DMV and find out if you state even has "special construction" and to find out about your state's rules, restrictions, forms and information.
Florida DMV DHS -- Department of Highway Safety -- Special Construction Process Information and Forms, Pamphlet Number One:
Florida DMV DHS -- Department of Highway Safety -- Special Construction Process Information and Forms, Pamphlet Number Two: