In-car entertainment in a GA aircraft?

[Practice Auto 3,2,1]

I suspect the cost of the mod to make the installation legal would be massively prohibitive.

A few years ago we installed Kenwood CD player/radios to many new Robinson R44 helicopters (all with an EASA Mod of course) They worked ok and operated as already stated by auto muting when any radio transmission was made or received. Towards the end of the new aircraft 'boom' Kenwood discontinued the model of stereo used and as such we had to change the mod. As it happened EASA decided not to allow use of an 'off the shelf' unit in the amendment (to the mod) and insisted that a purpose built 'aircraft certified' radio/CD player was used. It was crap and combined with the reduction in new aircraft being sold, very few were ever installed.

So to answer your questions. Yep it can be done. But you'll need a mod and that may very well be eye wateringly expensive (not been involved in them for ages so things may have changed - become cheaper)

I can't imagine your alternator struggling to run something as simple as a stereo. What might be a cheaper(?) option if you just want music is to get an audio panel with AUX input that you can connect an iPod/MP3 etc player to.