Ok, again some interesting new hints.
Thank you Keith! The lockable rack straps seem to be a very good idea and they´re even a bit cushioned to avoid scratches on the suitcase when the car moves and jiggles on the road.
I will ask if they also would ship it to Germany.
But also Dave´s solution with the Python cable looks fine.
Up to me now to choose my favorite.
Kind regards,
George
