You'll need to investigate your laws in Switzerland as the legal answer to this sort of consumer protection question varies by country.
IMHO, I'm a very risk adverse guy when it comes to making modifications to my Tesla that could in some way cause an issue, become a reason why Tesla could point the finger at me, or void my warranty if something went wrong. While I don't like that the TopFit camera itself doesn't come from a US Company with a US Warranty, my personal opinion is the chances of this device causing a problem with my Tesla are minimal. Unlike some other devices, this camera does not require any permanent change to my MS, and it does not require physically cutting or making a modification to a wiring harness, since it simply piggy-backs into existing power... If I should run into a problem, I can easily remove the camera as if it were never in place. I'll take that little chance. YMMV. Each of our tolerance varies.