 Purchased mine certified used with 11000 miles on it.  Very fun to drive!  Looks fast, is fast.  I rarely used to put the windows down in my old cars, but with this car I put the windows and top down every chance I get!  I get many compliments on it--it is simply a sharp looking car and turns plenty of heads. I love how Z4s are not as widely popular as, say, a 3-series and that was a big reason why I purchased mine.  If you're looking to buy, seriously consider the metallic silver color with premium package.  With the sharp angles of the body styling, silver looks beautiful!