Car Kit Conversion Question .. 3660

The car I bought has an in car kit and cradle for a Nokia 6310, does anyone know if I could adapt the wiring so that I could use this kit with my 3660? I'd like to ditch the old cradle and get the nokia 3660 one, and then hopefully adapt to charger and audio input/output from the existing kit to the 3660.

Most of those car kit boxes are just small amps, right? That allow you to run the loud speaker. The 3660 only has charger slot, head/mic socket and two other pins. Anyone know what these two are?