I've put in a couple in the last two years, one for my GT is a Sony digital media reciever. It's nice that it holds a standard iPod inside of it, also has a front USB port but the radio is pretty poor. In my daughters car I installed a JVC Digital media receiver KD-X50BT, think the new model is KD-X250BT, that sounds better & has much better radio reception, she listens to her iPhone music & Pandora using Bluetooth. I also mounted an external desktop cradle for an easy charging port.
Looks like the KD-X80BT may support the disk changer.
They both use the single big buttton input approach which I don't care for but seems to be THE Thang these days.