I agree with Ashman's idea. I think that is used somewhat commonly.
And Bobco was correct, I do have 4, but I wasn't thinking. I am only able to do this because my drive way is at an angle, and I pull the car halfway into the garage, thus more clearance under the center of the car to put the 2nd set of ramps.
I guess that wouldn't work for everyone though.
But Alon's idea is a good one (the 4 jack stands).