Mercedes and Phone Bluetooth

I have a new CLK with the bluetooth module installed for hands free phone. I am not a fan of using phones while driving but I get alot of emergency calls. In every other bluetooth equipped car I have used (BMW, variety of GM cars) once the phone is registered whenever you get back in the car the car and phone link automatically and receive incoming calls. Totally reliable, bulletproof, works with any brand of bluetooth equipped phone. Not so for Mercedes: sometimes it works as it should. Unfortunately much of the time unless I activate the system manually incoming calls will not automatically activate the bluetooth system in the car. Seeing how technologically backward Mercedes is about how Bluetooth is even installed in their cars I wonder if others have the same experience. If I had not seen how far behind Mercedes is about bluetooth technology I would not have believed it. Otherwise love the car.