Hehe. It is quite a long way away from "There is no way".
The input to to the tuner is a standard multiplexed stream. "Any" radio chip desgned for a RDS radio would do, and you would need something to control it, probably a PIC, talking RS-232 to the empeg and I2C or something to the radio chip, and then a handfull of "glue logic" and some consideration to RF and Audio parts (noise for instance).

Hugo had a short comment somewhere.

The easiest way... is to get a radio with line-out which is controllable through the serial port (or an external panel) and plug it to the AUX-in.

Marius (Escort Cab + Mark II)