Rex wrote:Sorry, for our digressions .
There is a former Q member (now M45) that's in the cell business, hopefully he'll be able to offer some real insight.
That would be me, I guess!
I had one of the original Infiniti phones in my 1991 Q45. Since the search does not seem to find it somehow, I will provide some info on it.
It was a Motorola OEM design, integrated with the audio system (auto mute when receiving and placing calls - neat!). With a rear antenna, remote cellular electronics (trunk), remote mic, speaker below arm-rest (in front of handset). An analog AMPS phone, of course, and service for these cannot be had today - none of the large companies will offer new analog service. About all you can do with that old phone is place 911 calls (this is a legal requirement - any cell phone can make a 911 call without having an account,) although even this is going to change in Feb 2008 when the AMPS service requirement is lifted by the FCC, and all the wireless companies are likely to drop analog in the major cities.
Using the rear-mounted antenna is not practical for new phones, of course, since it only went to the trunk area (where the electronics were). You could screw on an adapter and add additional wiring to the inside of the car to your new phone. However, most new handsets do NOT use a standard SMA or triax antenna connector (almost everybody seems to have a non-standard antenna unique to their model,) so this is kinda useless unless you get one of the car kits which might have such a connector.
In theory, the built-in Infiniti speaker and microphone might be usable with a modern cell-phone if, and this is a big if, all the impedances and efficiency (speaker) and gain (microphone) are similar to what is needed for the small combo jack used with "ear-bud" and other headsets sold today. My primary concern would be if the jack output on the phone had enough power to drive the speaker to any decent level at all - you would need an incredibly efficient speaker to make this practical, and I doubt that the built-in speaker is that way.
Since I no longer have access to my Q45 phone, or any technical info (the service manuals do not seem to cover the phone!), I cannot measure anything to tell you whether it will work. You could try it (handy with soldering iron to make the wires fit into one of the small connector that plugs into handsets!), since it is not likely to damage anything on the cellphone. The soldering would be a bit tricky, since the connector is tiny - find an electronic tech with a lighted magnifier and good fine-soldering skills if you do not want to attempt this yourself. Another possibility is to cannabalize one of these "over the ear" headsets and use its plug and wiring to connect to the wires in the car.
Good luck with this project! My suggestion is that it is more pain that it is worth (but when has that deterred the folks here? ). If you do attempt it, please let us know how it turns out.
Z