hmmm.... performance wise all these cars are very close to each other. The 350z is not really that much powerful then the g35. couple of horses more and a little more lbs-ft of torque. I would say that the g35 is very very close in performance then the 350z.

I meant to say "very very close to the 350z"

 

g35 is juss a 2+2 version of the 350z sold as the infiniti name. So alot of people who want a 350z who needs the back seats look at the g35. They share the same engine, but for some reason the g35's engine turns out a little less hp. The interior of the 350z can't be compared to the g35 and the rx8. I have sat in all three. The 350z's sound system sucks compared to both and the cheap plastic used in the 350z is nasty. Im sorry if it sounds like Im bashing the 350z, but Im just stating facts. The g35 does have a much better interior than the the 350z, but I found it to be rather dull compared to the rx8, the quality of the materials seems to be up to par on both the rx8 and g35.

 

"I just can't stop thingking about the heated seats.
I hate cold leather seats... OOO the warmness."

Does the Z have heated seats... emmm NO.
go get the 8. LOL. J/K
look at the best looking Z and now go look at the
mazdaspeed rx-8 again... that picture will make you forget about the Z.

 

350Z's with leather seats are heated!

 

My 2 cents worth.
RX-8 wins in the following:
1. Weight
2. Driving Dynamics
3. Uniqueness
4. 4 seats
5. 4 doors
6. Rotary Engine
7. Revving
8. Handling
9. Interior
10. Shifting
11. Pretty much does it for me

That is not to say the 350Z is undesirable. I love it too, I just prefer the RX-8.