...and ISO refers to the standardisation committee that produced the ISO standard (I forget the number) connector patterns for car audio components. So possibly, what you mean is that the M3 has got a DIN aperture and may/may not have ISO harness connectors for audio.

If you are paying the sort of money I would expect for a Beemer M3 (no matter what series) then if there is no provision for audio connection, you are being ripped off. I would argue the toss about this, as you will have to consider the costs of a build-in by professionals afterwards if you want to accomodate an empeg, amp and speakers. Be wary of the fact that the story about the wiring is true - think about your dealer warranty before letting people rip the dash out.

The Alfa GTV is faster and handles better anyway, even if the build quality isn't that good...