First, he is in Switzerland so let's leave the freq band issue to him as we have no idea what their rules are.

Second - NO-No on the antenna inside the carbon tube. It will shield the signal from the antenna and reduce the amount of received signal. I'd rather see him get more signal. I believe carbon fiber is one of the problems some of the jet guys run into. No foil either.

Third - don't ground any part of the antenna

Fourth - While I'm not a big fan of wrapping up antennas like Mike suggested, I have no problem with that on ground vehicles at known short ranges