I had exactly that set up in a previous car - my service provider gave me a second SIM and set it up so that calls would be diverted to the second SIM. Could also make calls from the Car Phone which simply went onto my account. Only problem was that person being called would see an "unknown" number when receiving calls from the car phone - solved that by inhibiting display of number. Apart from that - it all worked reasonably well.
However - I now use Blue Tooth from my phone to the car - and that's a whole lot better. There is a short "Bleep" as the phone pairs with the in-car electronics when I get into the car (I don't have to do anything), and then any incoming call mutes the radio and puts the call onto in-car system.
The installer had to get a wiring adapter from (I think) BMW so that it interfaces with the audio buttons set into the steering wheel so that I can pick up an incoming call and "replace the handset" after the call without taking my hands off the wheel. I seem to remember that it will also store regularly used numbers, but being of a similar vintage to BEagle (!) (not being a "teen-aged girl" that is!) I haven't bothered to enable that feature.
The Blue Tooth system itself didn't come from BMW - it's made by Parrot.
Might be worth following up?
BTW - Don't have a Nokia phone (tried one but found the menu after menu after menu system too tiring) - Am using a Palm Treo. I think that most phones these days offer Blue Tooth (which could be a bit balky at one stage but seems straightforward enough these days).
Last edited by Feline; 28th Jul 2010 at 08:26.
Reason: Added comment about Palm/Nokia