S2000 Musty and Mildew smell in cabin

[The Busman]

My newly acquired 2004 S2000 has a severe musty and damp smell in the cabin when the roof is closed. I bought the car from a dealership, but the car had the same owner for seven yesrs, only covering 1000 miles a year. Any ideas where to start? No obvious damp patches in cabin, roof in good condition. Thank you....

[dobly]

I would guess that water has got into the heater / ventilation system and is stagnating because of a blockage in a drain tube. I don't know how visible the drain tube is, but it should be accessible from underneath (part number 80275-S2A-000). Unblock / remove & replace.
Drive car with roof down & heater on (various settings) to see if it clears.
If it gets smellier, then perhaps consult an air-con specialist.

[dobly]

or it might be something like this: https://www.bbc.com/news/uk-england-essex-44520492

[The Busman]

Thanks dobly. Car goes back to dealer next week, so will ask them to check those specific points....... (Not sure about the cat, although there was a rabbit having a look at it underneath at the weekend,!)

[designforlife]

may be worth chucking a moisture trap or two in the cabin...used to have a lot of damp and mould issues with my mx5 because of the rubbish roof drainage design.

[Willy Nilly]

A new pollen filter too while you're at it.