Approaching 150K on my 08 G35S! 6MT! What to expect?
 

^^^

You should only replace what is needed. If no pending engine service codes, then focus on ancillary things.

How is the suspension, test with a crowbar or visual inspection.

Have you upgraded auxiliary lights to LED? Those look nice.

Consider stereo upgrades?

Any braking improvement from the Power stop brake kit?

As some already suggested, the suspension components.

Also, do an engine compression test to see if any cylinder is low on compression.

Also, if "All Fluids" excluded diff gear oil and trans gear oil, do those as well.

I'd listen carefully to the AC compressor. Mine self-destructed and I had to replace all AC system components.

I'd highly recommend Koni adjustable shocks from the coupe.

I don't believe there are any type of dash kits for the v36/G37 as far as stereo upgrade. Pretty sure everything would have to be 100% custom.