RAF = rear ambient fill

It's basically a load balanced output for rear speakers, ie. you can run 2 sets of speakers off the same 2 channel amp output, and get an attenuated rear speaker output for rear fill without changing the impedance at the amp. Tends to work quite well in smaller interiors, so it might be worth trying in the Supra.

Dominic

Cambridge Car Audio
http://www.cambscaraudio.co.uk