There absolutely were not more than 1815 made for North America. Z4M Coupe, specifically. Not counting roadsters and not counting world wide. World wide I think the number is more like in the 4000s, but can't remember exactly.
Ok, I'll find it for you - The numbers are widely available. Facts be facts.
http://www.bimmerfest.com/forums/sho...1&postcount=23
http://www.bmwmregistry.com/model_faq.php?id=24
bibbly has a good point. Values may plateau but it's going to be a long while before they really start to streak upward, unless something drastic happens, like M is completely disbanded or something, and that's not likely.
dorifto88 - have had the same thought. Even an M3 with the V8. Had an E46 M3 - that purchase was all about experiencing the S54. When we got it I wanted a Z4M but they were too new, couldn't afford one at that time. Couple of years go by, different financial situation, no plan for kids, Z4M became attainable. That's the quick story.
I don't want to regret selling it, that's my main concern and why it's probably not going anywhere any time soon.