I park in the garage so I leave my windows down 90% of the time so the air doesn't get stale inside the cockpit (yes I call it a cockpit...lol)

 

I leave my car outside uncovered (I'm working on getting a car cover). These past few days it has poured and there is no smell. Try airing it out and then covering it. You may have a tear in the top or one of the seals in letting water in.

 

Mine was soaked with the rain we had in the area here yesterday (weather man is a liar...slight drizzle my arse!). No smell or anything.

 

I live in Vancouver so my S2000 sees plenty of rain. Absolutely no smell inside. You MUST have a leak somewhere. Sorry to hear that. Look everywhere for moisture!

 

Take out the foam tool holder in the trunk and see if there is water sitting underneath it.

 

yeah, smell = organic stuff somewhere.

to get rid of the smell you have to find whatever it is and remove it.

 

I have had my s in the rain and no smell in the cockpit the following morning. Look in the trunk for possible leaks and check foot wells pass/driver side to rule out carpet being wet because that will create the smell.

 

1. Shin-etsu silicon grease on all seals.
2. Replace cabin air filter.
3. Check trunk under tools for standing water.
4. Run a/c full time when driving the car to dehumifiy the air coming into the car and vents.
5. Not sure how to do this, but check the drains in the cabin air intakes at the base of the windshield/top of the hood. They may be clogged and allowing water to enter the HVAC system.