the Z4 is good for the money, decent performance and good
handling, if they have the 4 cylinder version, good for fuel
economy too!
SC430 is jap.
Don't waste money on the M3 new, its already an old model. Go for a
330I sedan, lots of fun!
But if you want a roadster and don't want to spend too much money,
you have to consider the new mazda miata or MX5, its a great
drive!
slk over the clk, clk too lardy for me. Slk only if you want a hard
top.
Then again, the cooper S is a fun car to drive! And they have a
cabrio version.