[pairodice]

If you go UP then you would still need a ramp wouldn't you? I know your trailer drops down but is it enough that a Ferrari could get out the back without scraping? What about having the door fold or trifold up? Then you would not need as large of a mechanism... (???) These ideas are all free btw, so you get what you paid for :-).
The other consideration of having a door like that is the wind could catch it (?)