amsoil MTF 5w-30 here is all i've used in my my05 tranny taken my car to the track so you know the tranny get really hot so no problems here absolutely love it . 100% although i should give that 70%-30% a try just to compare, ty

 

I wouldn't mess with it to be honest.
If 100% works for your car - stick with what works.
Besides, you degrade the longevity of the fluid if you cut it with a conventional fluid such as Honda MTF. Straight Amsoil MTF will last longer than mixed.

Like I said previously - I believe every S2000's transmission is a little different.

Model Year 2005 in fact was the first year I think Aisin got the transmission right. It's listed as the most reliable year of the S2000 prior to '06 (drive by throttle mods). Every previous year had transmission reliability being the only low mark for the S2000.

I'm looking at getting my second S2000 (in addition to my current 2003 - which I won't let go) and MY2005 is my target year.

 

Yes.
You'll have to search for it or PM him for details. He made an adjustment to the clutch pedal related to it's free play. This adjustment solves many 1-2 grind issues, as well as some cold 2nd gear crunch issues.