Gadget,
Congratulations on your new purchase and welcome to NICO. I'm glad you've found the site useful so far. The J30 is a great car and a sweet ride. Post some pics whenver you get a chance.
I don't know about replacing the carpets. I think that it would be an expensive job to do. You may want to look into dying them to a darker shade of grey.
Call Joe at Scottsdale Infiniti on your floor mats. He gives great discounts to NICO members and is a member himself. His number is at the Infiniti Parts USA website
http://www.infinitipartsusa.com.
As far as preventative maintenance goes a transmission flush that includes and pan drop and filter removal is a good idea at least once a year. Also, fill with Mobil 1 ATF (the most recommended here on the site). Other than that, cleaning injectors, checking knock and O2 sensors, etc. the car should run fine. Dennis (Q45Tech) will chime in as will experienced J owners on this part.
The tires recommended on the site include: Michelin Pilots, Bridgestone Potenzas, etc. Run a search (big red button at top right) on wheels under Infiniti General and Infiniti Online Mechanic sections and you will find plenty more info on this.
Again congrats and glad to have you aboard.
Nick
