Had the quatros as i needed the height. Not a lot of choice available.
They are quite large to store.
Have seen many, including mine, where the front of the ramp has broken off, probably caused by driving over them.
Wheel cut outs are far to small to accomodate the wheels... hence difficult to locate .., However the best are Mikeco 3 . Not perfect but better .
Seemingly the designers are NOT motorhomers but .... Ok if ya have 12" diameter cart/ buggy.