Mold and mildew..........
 

Over the last few months, my 911 has not been driven much due to stormy weather and excessive heat. I have had to clean mold and mildew off the seats and steering wheel a couple of times. The car sits in my shop with the windows and sunroof open. Does anyone know of a cleaner that will help prevent this problem? I need to put a dehumidifier out in the shop but am looking for a short term method until I do so.

Fred. It sounds like you have an excess of moisture in your shop. I think that should be addressed as a first step. Maybe some others have tried some products to eliminate mild & mildew from leather (I'm assuming), but the only effective thing I can think of now is something with at least a weak solution of bleach. Years ago I had my car stored for quite a while covered with a car cover under a car port. I bought a product from H.D. at the time named something like DryZit. It was a plastic cup with a round cage on a stalk above the cup. The cage was filled with a material that looked like Styrofoam. It was placed in the car someplace like the floor board and the white granular material absorbed moisture which dripped into the cup. I had to empty the cup and refill the moisture absorbing material periodically. During the time I had my car stored that way, I never had a problem with mold or mildew.

Mold like any other living thing needs three things, food, water and oxygen. You need to get rid of the moisture problem or it will keep coming back.

Spores are absolutely everywhere and will germinate when the conditions mentioned by Hugh R are met. The only thing you can control is the moisture. If you install a dehu in your shop be sure the area is well sealed off from outside air or you will be drying that outside air. The dehu will run all the time with the consequent high electric bill and worn out early dehu. It is worth the money to get a good commercial grade dehu. The units sold by the box stores are crap and will not last.

A small heater would help. There's one called the Golden Rod that is used a lot in boats, safes, etc.
Might put one in the trunk as well.

Get a bag of damp rid granules (the kind that you can hang in closets) and leave it in your car, close the windows... SCs are airtight ;-) Empty the can/pouch of water before you go for a drive. ( Isn't there a coat hanger hook in that car? hang it there, can't miss it)

+1 on Damp Rid.

I use a couple of DrieRite 2 oz. dessicant bags that I get from work in my car foot wells, also in the camper for the Winter.