Just found this site for the first time.. WOW! A metric buttload of pics of everything under the sun. Check out the awesome shots of the Z3M & Z4M. Many of these I've seen, but a ton I have not, including the cool technical drawings for the Z4MC. Lots of great wallpaper material here...
http://www.netcarshow.com/bmw/1999-m_coupe/
http://www.netcarshow.com/bmw/2006-z4_m_coupe/
From the Z3 page: "The M Coupe was never loved by the market place and production was limited." Harrrrrrrumph!!