there are already tons of hot shot companies out there....just do a search...
Actually they've been calling it that for 20 years now probably. If memory serves correctly, DaveKC may have some experience from back in the day.
My carrier in Minnesota is a Quick-Draw dealer, and they do build a few each year. very few. and this is NOT general freight, but only for specific hauling. most time the same company will order 2 or 3 @ a time. sometimes i see st-trucks comes for repairs. they also did some smaller hot-shot trailers, the ones that are been pulled by PU trucks. again, this is for specific hauling and not to improve load opportunity. i don't think it is a good idea for hot-shot. unless you already know what it is you are going to haul. most loads that require QD {i.e side or top loads} are WAY too heavy for a St.Truck.
My previous (original) carrier had one leased on ... but they did a lot of steel hauling for a fabricator that did custom plasma cutting ...