I'm happy with this, finally after all these years i might get my money back when I come to sell mine in 4-5 years when the Alfieri comes out... (ironic smile).
I tend to agree with Phil in saying that the 3200 will catch up with 4200 prices but I can't think why! (another ironic smile!)
I'm also happy as my wife has a Z4, not an 'M' but it's a great car even in the 20iS form. The Z4M is the older E85 and is a rag top but the newer E89 Z4 has a metal folding roof which is better in my opinion. The new Z4 (F/G??) is rumoured to be a rag-top too so the E89 should still hold some value. And yes you can open and close it on the move...i did this the other day...but you have to go around 20mph or less and annoyingly keep your finger on the button.