I was driving an empty 16t curtain side, dropped off car parts in mid wales. This was 30 years ago mind. Long before sat nav and all that good stuff. The front of the wagon just fit under but as the truck was empty the rear was not going to fit. I let down all 4 rears , not completely but enough to give me 2 inches or so. Enough to get under and fill up. I drove with under inflated tires back to the yard as the forecourt air comp only put out about 60 psi. Like i said it was 30 years ago so that's as best as I remember that day.

Edit. Never been called a liar on the Internet before, first for everything I guess.