~ One man’s opinion / observations ~
Mildew / Mould:
Remove the seats and thoroughly clean the carpet with a carpet cleaner and a disinfectant. Then let it air dry, ensuring that it is completely dry.
The carpet backing will absorb the most, spray the affected areas with a disinfectant (both the carpet backing and the carpet) clean the carpet using steam extractors upholstery attachments, and then re-install the seats.
To eliminate the musty smell use an odour-neutralizing mineral made from porous volcanic rock (Zeolite®). This type of product absorbs odours, eliminates stale musty air, and will reduce any noxious oil or gasoline fumes. It is non-toxic and when it stops working can be re-charged by warming in a microwave or in the sun.
~Hope this helps ~
Knowledge unshared is experience wasted
justadumbarchitect / so I question everything/ Jon