[a nonymous]

I've actually had good experience using FM transmitters. I've found that it's important to choose a station that isn't actually a local station, or you'll risk interference. Try some different stations until you find one that's clean. It sounds good to me. FM transmitters are what everyone I know uses, and I know some people who are pretty picky about their music.

I don't know anything about other options. Hopefully someone else can help you with that. Obv would be ideal to have it wired in somehow, but I'm sure that's more expensive.