Nissans Nismo 370Z

for $40K I can think of alot of used cars I'd rather have
Porsche 911turbo comes to mind right off the bat

How about a Carrera 4S for $40k? Gotta go all the way back to 2003 model though. Local exotic dealer has this one.

If I was in the market for a new car, of course the RX8 would be the top on my list, but the new 370z would be very hard to pass up. Starting price of around 30k, 330hp/270ft-lbs, updated suspension and everything else. Nissan has truly brought the famous Z car back to sports car legend status.

I'd just try and find a miata and drop a roarty in it...  I've always wanted a tiny car that'll make you giggle and I've always wanted a rotary so why not just combine the two. 

or get the new one since it's sexy
2010 Miata facelift:

I see mazda gave the miata part of the smile it gave the new 3.
I have often thought about a rotary miata as well. I really want a rotary, and I really want a miata. Though I think I would rather have both cars, rather than a combination. A new RX8 and a Mazdaspeed Miata, I would be in car heaven. :)