That shouldn't be a problem. Most car audio companies will most likely have adapters for that kind of thing. If the changer is an Alpine, 99% sure an Alpine, or any other aftermarket deck for that matter, will be able to fit it just fine. Ask around at Circuit city, best buy, etc.
<span style='font-size:8pt;line-height:100%'><span style='color:blue'>1998 BMW 323is Coupe, Black
18" M3 Hyper Silver Rims
2 12" Rockford Fosgate Subs; Sealed
1.0 Farad Capacitor
800 Watt 2-Way Rockford Fosgate Amplifier</span></span>