Fitting for caravan mirror on VW Golf

My caravan mirrors did not fit the mirrors on my new car. Because of the shape of the mirrors the caravan mirror just slipped off. The rubber cushion always ended up at an angle and did not grip. One of the originals is shown on one of the photos.

So I made a new cushion that fitted better to the mirrors.

I made a test printed in PLA, witch actually works just fin, but I'm afraid that the hard surface will scratch the paint so I made this one using Nina Semiflex. I used 50% infill.