M3's are 3.2. 3k IMO wont get you anywhere near as fast as an M3. They are faster, I dont mean to sound like Im saying your idea is stupid but Ive spent the money. Im happy with what Ive got and its all been done on the cheap but Im happy with it as thats what I wanted. If I wanted to beat m3's and 911's then 1, Id be unhappy as id still be slower, 2 I would be just as much out of pocket.
I love the Z for the way it drives not its speed.
Also Ian is it faster than an m5 or e55amg? Do you see what Im getting at there is always someone faster than you.