Only you can answer this one. Several members started with a Z3, and changed to a Z4 and a number went back to a Z3, or were able to add on to their collection. Common comments are that the Z3 has more character whilst the Z4 is a more sophisticated car. Only way to find out is to drive the Z4 yourself (or you could buy both......well maybe).RIGHT!! I have now driven an MX5 2.0 and it was quite good but nothing special. I have also driven the Z3 2.2 and it sounded amazing, not quite the same power as the 2.8 but it still put a big smile on my face (that noise). Here's the pickle, Z3 2.2 or Z4 3.0, the Z4 seems to be more readily available for the money and gets good writeups, more headroom and more power. Opinions?