Very likely it's a leak (if it on;y happens when it rains). I had a similar issue in mine, and what it turned out to be was water was getting into the trunk, pooling in the bottom, and becoming stagnant.

 

Are you getting excessive condesation on the inside of the windows?

I'm agreeing with CKit too, changing a cabin filter = reducing vent odors.

Good luck.

 

I didn't get to undo theo trunk lining but It didn't look like her was any water damage in there.
I'll have to check on my day off next week.
Also haven't had the car for too long so.
I've only been in it after it has rained once.
Is there a DIY guide on changing the cabin filter.
If it's no too hard I'd wanna try it myself.
Also where do we buy them?
And are they s2000 specific?

 

Cabin filter DIY is in the FAQ in the Under the Hood forum

https://www.s2ki.com/forums/index.php?showforum=22

 

Dude,
If you may have water pooling in the trunk why would even consider waiting until next week to check it?
It takes minutes to peel back the carpet and feel around - right?

Make us proud and figure it out.

Cabin filter - great idea!
Shin-Etsu grease - we all need it anyway each year.
Interior condensation - do you have it? It tells you alot!

Report back

 

was gonna peel it back this morning. but i already had to leave for work (walk/skate)
and i dont get home till 1030-11pm.
makes it kind of hard to check.
especially when trying not to wake up the parents who sleep right next to the car.
but you're right.
i'll try check it tonight!

 

i have this issue too, but it only seems to come up during very heavy rain. the smell is more then likely your carpets getting mildew from being wet.

shin etsu grease improved the issue about 80%, but i still get a little water inside when it rains hard.

 

ok. so how do you remove the clips with out breaking them.......they're so fragile.

 

$5 trim tool from Autozone. Looks like a flat fork.

 

I get a weird smell only when I turn off the car without turning off the AC.. may be unrelated though.