I'm guessing from the 300hp question that you are looking for a new 350z.
The Track and Ann. version get the extra HP but have less TQ. There is talk about them also getting stronger rods, but I have yet to confirm that.
I picked the Enthusiast 6-speed because it had what I wanted, LSD and HID's. I also wanted the Brembos but at the time didn't think that the extra $ would be worth it. Then I priced brake upgrades.
The performance gets the 18" wheels and tire pressure monitoring.
Touring adds the Bose and leather seats (I think leather is an option now on the Enthusiast +).
Yellow is an extra $500.00 which is a bargin if you look at what the liquid aluminum was for 2004.
The 350z is a great car that I would recommend to anyone looking for a $25-$35K 2 seater (
zerothread?id=94257 ).