The MB kit clearly states that it is a SAP device (I had a look at the specs this weekend). I
had hoped it would work with other Bluetooth phones, but clearly not judging by the posts here.
Also, Tony Purslow Guildford had sold a couple and found out the hard way that these kits do not work with ordinary Bluetooth phones.
However, this is not MB being behind the times. SAP is very new - very, very new. I hope that more and more phone manufacturers will start to include the SAP Bluetooth profile in their phones soon (I bet MB do, too

) but we must now wait and see.
As a matter of interest, the first car in the world to support SAP was the Flying Spur - last year. As far as I know, only the Volkswagen Passat, Bentley GT range and MB have SAP systems for cars at the current time.
So far, I have checked out Samsung (no phones) Sony E (no phones), Nokia (a couple), Siemens (quite a few - all defunct), Motorola (no information available). If anyone discovers any SAP phones, I would love to hear about it.
Philip