We have a Kodiaq and it's more than enough to open the tailgate, I don't think that should be a problem with the Opel.

Here you can see photos of a VW bus. Scroll up briefly: https://thecycleverse.com/de...

I have a Marco Polo.
Go to mp-mylife.com..... who also sells the carrier. There's a video for it on YouTube. It explains everything . The carrier is top .....