I just got my S2000 in December. I didnt have much problem with it, it was my first manual car. I thought that i was having problems with 4th gear because once in a while it just pops out of gear. Its been about 2 months since ive been drving it and now it does it almost all the time in 4th gear. Just goes to neutral and i ll be pushing on the gas and almost red lines. I brought it to get checked out and they just looked as me as if i was retarded because they couldnt find anything wrong with it. My friend just drove it and he had the same problem with only 4th gear. If anyone has any thought please tell me.

 

First, you should edit your title. "Clutch pops out" isn't what you are trying to describe. "Popping the clutch" is a technique used to launch a manual car.

You need to go back to the dealer and show them that it pops out of 4th gear. Insist you take a service guy with you and you do what you normally do to get this to happen. Then they can duplicate the problem or show you what you are doing wrong. If this doesn't give the desired results, go to another dealer that may have more experience with S2000's.
This has been reported before and there is a fix for it.