I had real problems getting the Motorola unit working with the original becker unit so I went for the Pioneer Bluetooth unit - the installer made a wiring loom so that i can plug the old becker back in future - not that the car is going. The sound is fantastic, and the phone function is great - i have the mike installed just above the steering wheel so the wind noise with the top down is okay.
The Ipod function is great.

I just want to put some two 6 inch speakers in the bulk head behind the seat - i need to see how much room there is.

Cheers