It would most likely hold. But you have to remember that in order to clamp the mobile phone, you have to be able to spread the holder. Depending on what kind of mobile phone you have, the holder + mobile phone together will be wider than the fan, and the "grippers" will no longer reach to the back. The clip for the fan is exactly 2 cm long.

The fans look very flat in the picture. In my case, they are "recessed" a little further, so I'm a little worried whether the brackets actually reach that far back. But I'd still be glad to have them measured ^^

Well, I installed it in the A6 and it holds very well and I can recommend it...

https://www.google.ch/search:

If necessary, I can measure it for you ;)