Re: FOR SALE: Rare Becker Monza!!
The top connector for the Becker unit is for Pre Amp out/Telephone/CD Changer.
If you only use the bottom two connectors on your unit, it should work. If your top connector is only for your car phone, as 04Fire said, you may need to do a little re-wiring.
If you know someone who lives close by with a Crossfire head unit willing to let you hook it up for a test, you will know instantly if this unit will be plug and play in your console.