I believe mk2 navi uses c43 radio and mk3 and 4 uses bm53 radio.
You will need to buy few adapters to make it work.
https://www.ecstuning.com/BMW-E39-M5-S62_5.0L/ES162650/
https://www.ecstuning.com/BMW-E39-M5-S62_5.0L/ES162649/
https://www.ecstuning.com/Search/Sit...4785/ES162779/
Having said that, $100 for whole mk4 setup is SCORE!