I also have the 9504 (3 bike version of the 9502) picked it up second hand for circa £90 few years back. Been using it few times a week ever since picking it up, dont know why I never got one sooner!
I have an XL 29er and it fits on it fine, slight balancing act before you get it strapped in, but with use you get really slick at loading up! The wheels on the Xl 29er do poke out past the width of the car body on each side, but no more then the wing mirrors.
Ive done all sorts of miles using it covering A roads, motorways and country lanes, for example Ive done Exeter to BPW with my XL29er, whyte t130 and a DH bike, there were no issues. For extra safety, I did use a ratchet strap to go with the stock straps.
The rack does say limited to 45kgs and a max speed of 80mph but I’m sure I have gone over this and haven’t lost a bike yet!
The stock straps that came with it where n’t too great, I picked up some fasty straps as recommended on here and they have been great.