When I tested Monster’s “iPhone compatible” tape adapter, I expected the $25 setup to have extra shielding to stop GSM buzz from the cellular radios. It didn’t. As a joke, I tried some anti-alien brainwashing technology, or aluminum foil. Turns out wrapping a bit around the first few inches kills off a lot of the louder spikes in GSM buzz. Tragic it took some Reynolds Wrap to make my shiny car and my $600 iPhone work well together, but I no longer have to switch to airplane mode or risk blowing out my speakers with EMI bursts.
https://gizmodo.com/monster-icarplay-tested-with-iphone-verdict-gsmbzzzz-278346
