2-to-4 channel adapter for standard / radio only wiring premium wiring This is a limitation of

This is a limitation of the security circuits on the main radio board

NOTE: you will need to remove your OEM trunk amplifier

com to confirm your radio model is supported

If you're making the wise choice to return to a factory BMW radio in your E21

This is the OEM mounting hardware needed for the factory Blaupunkt QuadroBoost trunk amplifer

2-to-4 channel adapter for standard / radio only wiring premium wiring This is a limitation ofExactly equivalent to BMW part number 65 12 1 379 329. Plugs into fader connector of a 2 channel standard radio only audio system. With this adapter you can run an OEM 4 channel radio like the CM5908 or KE83 ZBM without a trunk amplifier in a car with 2 channel radio only wiring. Also compatible with Amp+ if your car has 2 channel standard radio only wiring.