Welcome to the board! Yeah, you'll get lots of advice here. Some of it will even be good advice.

With no records you should baseline everything - change the air filter, oil/filter and coolant for sure, and optionally the interior air filter (behind the glove box), brake fluid and the rear diff oil. Check your suspension compinents as others have suggested, and keep your eyes on the forum because stock suspension parts come up used quite often for cheap as guys upgrade theirs with aftermarket goodies.

Read the stickies and FAQs before asking questions, because this is one of the most comprehensive car forums I've ever seen - 99 times out of 100 someone has already asked whatever question you're about to ask.

And if you go to any Infiniti dealer in the US with your VIN they will give you a print-out of the complete dealer service history from any dealer in the US, for free. It's a good place to start to confirm any recalls were addressed, and how meticulous the previous owner(s) were. Depending on how long the car was dealer serviced it's also a useful way to see when major wearable components like the clutch were replaced, if at all.

You're going to love your G. I've had mine for four years now and I still love getting behind the wheel.

 

That's funny - my one-owner Florida 04 6MT is almost the same story (but with 85000 miles). Window sticker and everything! Got it from a Ford dealer who had it for three months because "nobody wants a manual 4-door". Got a smokin' deal.