Hi

I have a Citroen C3, which came with a Clarion RD3-01 (PU-2471A(E))
CD-radio. I already had a Sony CDX-MP30 from my old car, which I would
like to put in the C3.

I've tried fitting it, and it does connect up OK, and plays fine, but
it seems to confuse other things on the car - specifically the car
alarm doesn't work properly (won't turn off with remote, etc).
Replacing the original Clarion stereo makes the alarm work OK again.

Is there something I could do to make it work properly? I've asked my
Citroen dealer and they say they can't do it, but I'm hoping someone
knows better.

Alternatively, what's the best way to add an AUX input (feeding in
from a personal MP3 player, say)? FM modulator, or something like
that?

Pete