I don't know that I'd want to do that with most ramps. With no support in the middle there could be issues with the door bending. I suppose if the door were strong enough it would work, but I'll have to admit I've never seen one in use or even advertized. My first thought is "No Way".
Are you having trouble getting it up the ramp and over the hump? What kind of vehicle are you planning on using? Or are using now?
Maybe I'm just having negative thoughts and some others will come on with some more positive vibes.
๐
Howard and Peggy
"Don't Panic"