Summary: Only an option if you have an older car and don't want to put a new USB deck in (or the car's wiring simply won't take one), and don't want to burn .cda/mp3 to disk (or use a cassette adapter). It's a trade off, you get access to a huge catalogue on your player but the sound is somewhat diminished.
Pros: -Auto-tune to clearest empty stations, -Has a Pro/mono setting for a bit better audio for audiobooks/non-music stuff, if you need clearer audio for that.
Cons: -Audio is limited by the technology itself. Can only be so good., -Volume is usually quite low, you can max your car stereo AND mp3 player occasionally and it will not be that loud, -Bit of static, hard to avoid