CJ-
This is the ramp that I was interested in last fall to use in my garage, to get into the house. My thinking was that I could also use it so Jim could go out the back door to the patio. Only Jennifer from UK said she had one (and her link showed it really wasn't the same).
I wanted to see it first- let Jim test it with his chair & let me test the "portability" factor.
But checking the weights given for different lengths, this didn't seem feasible for me. (and I am a much "bigger girl" than you, and am not a weakling! However, the size for a vehicle would be shorter, I would think)
The problem was I couldn't find anyone except a guy from Long Island (NY), who at first said he would drive down to us (?) and then didn't "get back to us".
I know they show it's use for car/van; we sent for the info from the company (including a DVD demonstrating the different applications).
If you do decide to go this route, google first. I found lots of places that had it for sale that was less than the price directly from the company.
In the end, we built a permanent ramp. It cost the same as the discounted price of the roll-a-ramp would have cost us.