I was noticing that they didn't have the "Forged" stamped on the rims. I believe all OEM Nissan/Infinity RAYS wheels had the "Forged" stamped on them.

 

http://www.oewheelsllc.com/

He's mentioned that he's got them from this website in one of the thread so he knows it's not the OEM Infiniti G35 forged wheels. The set he has are replica 18's as opposed to 19's like the originals.

 

the 18"s came on the sedan. They are not forged like the 19"s, but I weiged them in at 21lbs. not bad.

 

Ahh it all makes sense now. Still good looking rims

 

It doesn't seem like anyone's really answered the OP's question enitrely
I've had 350Z touring-wheels for a few years now, and have never changed the "Nissan" cap due to laziness.
However, I'm buying a fresher set of 350Z wheels soon, and figure I may as well change them immediately.
So does anyone know which cap (or from what wheel) would fit equal to a 350Z cap (54mm)??

 

Easiest and cheapest thing would be to search ebay for some generic caps for those wheels, then either leave them blank or put a Lexus sticker on.

 

^ had some g35 wheels on my old sc400, bought chrome center caps from ebay. looked good enough, I didn't bother with emblems.

 

Same here with Mustang Cobra wheels.

 

There's caps out there that will fit inside the wheels. Plenty of people have done so. Or simply leave them out and call it a day