On my Armatuenbrett it is without adhesive properties on only loosely. However, the rubber surface and does not slip, so I'm actually even can use it as planned. Until the first violent braking, then fligt a mat including Navi around the ears.
My Navigon (large XL monitor, mini-USB connector on the bottom) fits in perfectly. But again, only a certain braking effect of the gums, no adhesive properties. The Navi ligt so loosely it.
In the end I can spend hours driving on the highway, and the holder does what it should. Navi fits, holds where it should, looks neat. But I have to avoid heavy braking and sporty curves, then there is no stopping them.
Supplement, I still have another self-adhesive universal holder. Here, the rubber mat glued actually like hell. But only on some materials. Now I dache clever, I put this adhesive mat underneath Duch, then it would have to keep super. But none. Even with this adhesive mat this Navihalterung denies the connection. Too bad.
Conclusion: Actually a good idea. I still want to have something. But it would have to halt hold what it promises. But this is your concern for safety and security.