I need to replace the back/rear box on my nissan 350z, only problem is nissan want around £500 just for the part. My question is, where can I buy an aftermarket back/rear box for my 350 for a more reasonable price and which ones fit. I've seen a few 'universal' fit exhausts but none of them look like they could fit. Any help would be thankfully welcomed.

 

sounds like you want the axle back section of the exhaust-check on
the marketplace section of this site-you might find someone selling
thier stock exhaust because they upgraded to an aftermarket one
i sold mine to another member last year-his got damaged and was
glad to buy mine(mine only had about 1k miles on it and was perfect)

otherwise look into purchasing one of the many aftermarket oem style
y-pipe back systems that have the two tip large box/canister style
setup, you might should even consider getting the nismo system-
looks similiar to stock-has a little more sound and i have seen some
good specials on the marketplace section of this site