Clarion commonly use two different connection types - C-Bus and CeNet.
Most lower end stuff is C-Bus, which uses a round 13 pin DIN
connection, which hasn't changed significantly for a good few years
AFAIK.

Do You sell, or know of anyone who sells *any* c-bus compatible Clarion
MP3 Head units?maybe some old stock? I can only find them with the
c-net connection, and a c-net to c-bus convertor costs £60 quid!!!!!

Austin