if you cannot decide, go for the new car :)

Such a tough decision for a lot of us.

If you plan to leave the cars stock, I'd go with the Z. If you plan to lightly modify, the 335 - heavily modify, the Z.

I plan heavy modifications by the time I'm all done ($10K+), and my daily driver is a 4 door that gets 30+ MPG so the Z was the right platform for me. Using it only as a weekend car for 6 months and havent' regretted the decision at all.

Good luck, you really can't go wrong with either car.

I've had both. If you need more room, go with the Bimmer. If you just need 2 seats and don't care about the road noise, go with the Z.

My personal observations...

- The Z gets a HELL of a lot more attention. People tell me everywhere I go what a sweet car it is.
- The 335 handled more predictably, although it was slightly softer. Make sure the 335 has the sport package if you get it.
- I can see the radio display on my Z with polarized shades. That's nice, considering BMW still hasn't figured out how to solve that issue.