I have a brand new in box OEM Nissan in-cabin microfilter that fits the G35. My Z doesn't use one so I no longer need this. Its recommended to be changed every 15K miles and they sell for around $30 at the dealer and on-line. I will let it go for $15 shipped in the lower 48. Send me a PM if interested.

 

what happened to your G35C?

 

SOLD! My G35C was a total loss after an accident.