A while back, there was a company that was making a third party cell phone kit for the A4. They used to advertise in the product section, by I did not find them there. Does anyone konw how to contact them?? Thanks Much!!<p>J

I'm pretty sure they closed down so no can do. There is a guy David Pincus (who frequents this forum) and he made something (I think) that might help you out. I think I saw it in the Sale section of the Classifieds or do a search in the archives for his name.<p>Jason

After the Cellular Integration stopped selling the A4 Handsfree kit, they decided to make their "secrets" public so people could build the same kit themselves if they felt like it. Here is the post with the details:<p>************************************************** **<p>Since we announced the closure of Cellular Integration, a number of you have requested that we "share our secrets." Here you go:<p>The A4 was designed and prewired to accept a standard Motorola car phone with a handset physically (not electronically)customized for Audi. The phone is located in the trunk, plugging into a DB25F data connector behind the driver side trunk trim panel. The handset goes into the console, plugging into a RJ45 phone connector that is under a small trim plate.<p>The DB25F in the trunk is the key to the entire installation. As the only interface to the factory phone, it has all the signals needed, IN ONE PLACE. It provides +12VDC (both battery and ignition switched), ground, microphone, speaker, muting output to the radio, and eight wires that run to the RJ45 in the console. All this is shown in the 'phone system schematic' posted in the A4.org FAQ. (Note: the RJ45 connector pin numbers given by Audi in this schematic are the left-to-right reverse of those used in standard telephony practice.)<p>Keep in mind that each kit for each phone is slightly different, each being wired differently. You must, therefore, go through the entire design exercise for every kit type being interfaced (even the "same" kits undergo design/wiring changes over time and must be re-evaluated at every occurance). The directions below are as specific as I can get.<p>This being said, here's how to do it:<br>- Buy a handsfree kit, for your phone, that has an external speaker and microphone (this type of handsfree kit already has all the driver circuitry you need). Throw the speaker away. Save the microphone, as you may need it later.<p>- The leads from your handsfree kit cradle now need to be connected to the proper pins on the DB25F in the trunk.<br>If there are less than eight wires needed by your kit, they can be routed to the trunk via the installed handset connector and wiring. If there are more than eight wires, you will have to route them yourself.<p>- If using the handset wiring, fabricate a DB25M that loops the signals form their source/destination pins to the proper pins (selected by your own cradle-to-car wiring scheme) of the RJ45. Put an 8-pin RJ45 on the end of your cradle wiring to allow it to plug into the console.<p>- If running the wires yourself, make a harness, with a DB25M connector at the end, that connects your cradle's wires to the proper pins on the DB25F carphone connector in the trunk.<p>- Mount the phone cradle, plug everything in, and you're done!<p><br>Notes:<br>- Make sure to observe proper electrical practices (fusing, wire gauges, etc.).<p>- We have experienced impedance matching problems between some handsfree kits and the Audi microphone.<br>In these cases you will need to use the microphone that came with your kit.<p>The process is simple for someone with an electronics background. However, IF NONE OF THE ABOVE INFORMATION IS CLEAR, QUESTION WHETHER OR NOT YOU WANT TO ATTEMPT TO DO THIS ON A<br>$25K-PLUS CAR.<p>Good luck! <p>************************************************** ***********<p>You may want to print that out.<p>Matt