X3 March 05 vs April 05 Production
 

I have two X3's, one is a March 05 production and the other is an April 05 production. In the April car, pushing the voice control button on the wheel allows voice control over the phone. The button on the March car does nothing at all.

Why? Is there anything I can do about it?

Thanks!

You can get a new voice module... I think. Someone please correct me if I'm wrong.