Two simple questions :D
 

1. I own a 2010 Sport. My Z is not equipped with an in-cabin microfilter. Is this normal? If yes, then can I buy it to add?

2. As I know this Sport PKG is equipped with VLSD (limited differential). How long is its fluid change interval? I already searched this forum and 2010 370Z maintenance guide, but failed to find it out.

:rofl2:

Check the diy section for the micron filter. U can put one in

As for vlsd not sure.

30,000 miles for the rearend, Max.

Make sure you have an extremely long screwdriver for the cabin filter install. It's easy but lots of people break stuff because they don't have the proper tools.

No idea. I changed mine around 50k miles. I'm not the original owner so I assume I was the first to do it.

Changing the diff fluid really depends on hard you drive your Z. Normal use including occasional spirited driving, 30K should be fine. Any track time and/or hard/aggressive driving on curvy roads and it will be less. Sometimes a lot less. I burned my diff fluid during my first track day with my Z which was also my first time on a track (only 6K mile on my Z at the time). I didn’t burn it bad but it definitely was burnt when it was changed at my buddy’s shop a week later. The factory VLSD tends to burn diff fluid under heavy use. Before my buddy put a Quaife in his Z he was changing his diff fluid at the track before he went home after every track event. This is heavy use we are talking about. Most people will not even come close to driving their Z hard enough for this to be an issue.