I think the spec docks have to plug into another module. I remember looking at them on the Bavarian Soundwerks site. I was considering it when I ordered the Dice but I opted to mount my Dice in the truck on the rear firewall and run the iPod cable through a small hole in the rear of the centre console. I actually bought an iPod Nano to leave in the car for $120.
While I was at it, I also installed a 12V port in the back of the centre console and keep a dual USB adapter plugged into that port so I can charge phones, cameras, etc while out and about but keep them concealed (and locked up) when I walk away from the car even if the top is down.
I do like the 10 speaker setup but I have heard great things about the speaker kit from Bav. If I hadn't just had to replace my top motor/pump, I would have ordered it. Next year!