This unit has not been installed in a car so it has no wear on the front panel, thus appears as brand new visually when installed.
The BT5100 was a 2008 year release car stereo with stylish joystick navigation and Bluetooth phone hands free with good usability as the major new novelty. It can auto-answer a mobile phone call and put voice out in car speakers and car mic input for a hands free driving experience if so desired. You can connect your phone audio with Bluetooth and have your phone music app connect and stream onto the car stereo as you enter the car.
RDS radio.
CD reader can also play MP3 files off CD. No MP3 memory card slot on this unit; only off CD.

The model is suited for contemporary cars with 1-DIN rectangular radio slot. I used a BT5100 with great success in a Jaguar X300 car. This particular unit has not been installed in a car but only run off some bench in testing. So the front panel has no signs of wear at all. It comes with a remote control and that unit has a small dent in the plastic, not much noticeable. Wiring has no signs of wear.

User Manual (English) here:

https://tinyurl.com/user5100

These were around 330 dollars retail when they came out in 2008.