A Yakumo car stereo...
Great fun, as it was not so obviously broken that it was worth returning immediately. It just gradually became apparent that every single feature was subtly (or not-so-subtly) flawed. Some lowlights:

- It switched to absolute maximum volume occasionally. The only way to stop it was to turn it off unit as the volume control now did not work. This was actively dangerous, especially if it happened in heavy traffic.

- It often "forgot" it has a CD drive. The only way out of this was to do a complete reset, which removes all of your radio stations and EQ settings also. This happened approximately once every 10-15 minutes of playback.

- It does not remember position in a track if it is more than about 5 minutes into the track.

- When playing tracks in Ogg Vorbis format (like mp3 but not evil), the first and last second of the track is truncated. This a particular problem with audio books.

- Display backlight was at first infuriatingly bright, and then both bright and faulty. Flashes at irregular rate, which is distracting when driving at night.

It by this point being out of warranty, it went to a car boot sale and was sold for £5. I replaced it by one from LIDL, of all places, and that's been as good as gold.
( Amish Information Systems hates misplaced, commas, Thu 29 Sep 2011, 13:14, Reply)