Randomly last night I noticed the car would hesitate or bog out when letting go off the throttle. The car sat for about 3 weeks and yesterday was the first time I drove it since. It's a 07 w. 81k miles, only modifications engine wise is just a test pipe.
[media]http://youtu.be/hCm19HdMq3A[/media]

Tried to capture it last night.

 

any input?

 

Based on experience with other (non-S2000) cars I've owned, the first things I would do are:
(1) Ensure you have a clean air filter and clean out the throttle body of any foulant, especially near where the throttle plate rests in the almost closed position.. If no obvious fouling found
(2) See if you have any check engine messages

The above is a bit of a stab in the dark. I had an older dodge caravan that had a throttle body that had to be cleaned occasionally. Small amount of carbon buildup would mean that when you let off the pedal and the throttle plate almost closed, there would not be enough air flow passage left for good air / fuel mixture and the car would act funny like you are seeing. Of course this is nothing like an S-2000 but may be worth a try.

 

Hello

Check out this page, it likely relates to what you are experiencing:

https://www.s2ki.com/s2000/topic/804...#entry19967418

Enjoy and take good care of your car!