Hi Mate,

I just tried the amplifier on it's own, with nothing but power and a speaker connected. Still whistles. It's a VERY noisy environment in the trunk space.

I think both the processor, or the amp will pick up the noise...

I still get the noise come through the amp, even without any cables except one speaker, and power connected.

----
I tried putting low ESR capacitors near the alternator to try to suppress some noise at the source. That didn't work. Tried putting some caps on the supply lines in the trunk space; still no good..

Pretty stumped what the hell to try next. Building a bloody faraday cage for the whole thing?

Any ideas please chaps?

Cheers
Scott.