An ISO connection is an industry standard connection. It doesn't matter what car you have, the iso connection will fit the radio you have bought (as long as it has an ISO connector) The power and speaker wires are in the same position on the connector/socket accross the board.
Thanks very much for your most informative answer.
I need this info. because I would like to replace the radio/cassete in my car (Citroen Xantia) with a radio/CD player, and I need to control its features from the present arrangment that is from the steering wheel. I wonder if this is the connection I need to be installed on a new radio/CD player. ?