We had a Thule ‘Clip-on’ boot rack for years and it was one of the most solidly built and stable racks we’ve owned. It murdered the paintwork on the car though.
I also had a Thule Clip-on for my VW Touran. It carried 3 full suspension bikes no problems and never moved an inch. Absolutely rock solid as mentioned above.
Luckily I put helicopter tape over the rub points on the tailgate so my paintwork was fine.
Would definitely recommend one to anyone.
The only downside was the rear windscreen wiper couldn’t be used. I had to remember to switch the wiper off before engaging reverse to ensure it didn’t automatically start.