In Episode 09 of the Quest for Perfection on the 1997 BMW E36 M3 sedan, we perform an upgrade and installation of the BMW OEM CD43 radio head unit and remove the stock C33 head unit from the car. This removal and installation is relatively straightforward and should be plug-and-play for most BMW E36 vehicles. Improved FM reception, sound fidelity, loudness, Radio Data System (RDS) information, and in-dash CD player are just some of the improvements of this head unit over the C33 unit.
The CD43 head unit was never offered on the BMW E36, but was later introduced on the BMW Z3 around year 2000. Despite this, the head unit works well in most E36 vehicles and is backwards-compatible. It will work with either the standard BMW sound system of the Harman-Kardon Sound System. It should also control factory BMW CD changers — with certain restrictions. If you have an older E36, you may be forced to upgrade to a newer BMW CD changer from a later E36 model.