Hi, just havign a play with my sisters car, it has a nice quality Pioneer 6 stacker CD changer in teh boot, which is about 10 years old, unfortunately this means that it is an M series stacker, and the old headunit is stuffed, so we headed down to cash converters to get a Poineer headunit with the stacker control, got a nice flashy near new one, unfortunately it turns out it has a different bus, P instead of M (11 pin square instead of 13 pin round)

does anyone know if there are adaptors to make the headunit work with the stacker?

No

bugger. looks like its time to hunt for an old headunit, because I dont feel like fitting a new wirign loom at the moment.

do any other companies make headunits which are compatible with the older pioneer stackers then?