It's been our impression that the factory systems have some limitations on functionality. We have had a lot of success with our systems and have only have had positive feedback from customers who have purchased. We sell the itronic units. Here are some of the features for your car:
The iTronic™ BT handsfree Bluetooth phone solution works just like a Mercedes Benz factory installed phone system. It includes full caller-id display and phonebook use1 in the car's built in radio and instrument cluster displays. The iTronic™ BT kit is a solution that allows you to use any brand phone and allows you to choose any carrier you desire. In addition, it allows you to simply get into the car with the phone in your pocket, purse, or briefcase. When you start your car, the car will automatically connect wirelessly to your phone. It is the only certified aftermarket bluetooth phone system for your Mercedes Benz. Full integration means, using radio or steering wheel controls to dial, accept/reject calls, browse the cell phone's directory, voice dialing, etc1. In short, it is designed to work just like a factory installed system would. The unit simply plugs into the network connection that is under the cd changer in some cars or behind/below the glovebox in other models. Installation is straight forward and simple. It does not require any cutting or modification of the car at all, therefore does not void any manufacturers warranty. The unit is also completely hidden after installation. No unsightly boxes or displays, just like a factory installed system. Many people ask if the car needs to be pre-wired for a phone system...the answer is NO!!! With or without phone pre-wiring, the system will activate all the original factory phone functions intended for your car.
Let us know if we can assist in any way.