Boat trailers are another matter. A friend and I have both experienced numerous ridiculous problems getting used boat trailers registered and titled in Colorado. A minimum of three trips to the DMV!
You should try titling and registering used trailers in Maryland, especially if the trailer came from out of state (and it seems you always end up traveling to buy a cat from somewhere else). I'm convinced the trailer dealers must have some lobby connection, because in some cases it's far easier to trash your existing trailer and buy a new one. Seems to have gotten worse the last couple of years.