I think my car is moldy! (chev sprint)
 

There was a strong strange smell which I couldn't recognize inside. I covered it up with an air refreshener for a few days. At one point I thought it was a bit like a mold smell. I sniffed around different parts of the car looking for the source and found some brown stuff on the sun visors and the ceiling above them (which is made of some sort of vinyl or plastic).

I'm not sure what the best route for cleaning it will be but I'm planning to give my car a total clean this weekend. Things I want to clean...
~ floor under seats, lots of dust and dirt and cob webbs
~ fabric on seats (if possible), visibly dirty
~ air ducts (if possible), when I turn on air I get seeds from trees blowing in?
~ ceiling, get rid of mold!
~ walls, dash, inside of windows, etc, general cleanliness
~ exterior... wash and wax

I have never done any of this before, never owned a car before, so any comments are welcome. I'm also wondering, is car mold a common issue or something you have had before?

interesting. good luck. just don't mess up any of the electrical stuff.

Most cars don't mold like that unless they have been sitting with a window slightly open or have an issue like a leak that is letting rain get in, so first thing to do is get the car dried out if it is not dry already, then use vinegar and water in a spray bottle to kill the mold, you can also use a table spoon of bleach in a half gallon of water, but I would not use that on fabric, vinegar is fine tho.
Air ionizers will work as well, put one in the car and close the door for a few days, get one that is designed for use in a home and it should burn up the mold and the smells and everything.
For carpet you can also use baking soda (not with the vinegar tho) and brush it in to the carpet then vacuum it out, it will pull odors out.

really? Vinegar kills mold? Good to know. Thanks.

Great information thanks. My car was missing a window when I bought it, which might explain how mold got started.

after you do a good cleaning, sprinkle a bunch of baking soda around and leave it for a couple days. Then vacuum it out.

...liberal applications of spray LYSOL worked for mold in cars on Guam!

To deep clean one of those carpet cleaning things you can hire for the weekend is superb. We got together and did a few cars all at once for the price of a single hire.

My car has white seats and I have a kid - the two mix too easily :(

I've done lots of interior cleaning today.

~ Would like to clean the seat rails since they look like ****. Not sure how to get rid of the buildups on the metal.
~ Would like to clean the air duct system if I can find how to get in.
~ Have not found how to completely remove the scuffs and marks from the vinyl on the interior. Will try some other cleaners then take it to professional detailers and ask them to do it for me if nothing else works.

Hopefully it will be warmer tomorrow so I can wash and wax the exterior. I need my car to look good just once before I dirty it in my own way. :)

for the ducts, look at this thread:
Stop the stank before it starts. - Drive Accord Honda Forums

on the seat rails, you could spray them with carb cleaner, but then whatever ran off would get in the carpet. And you would need to re-lube them.

Well my ducts don't smell that I've noticed, just when I turn on the air there are leaves and stuff blowing into the car. :( I'm not sure how this stuff got inside and hoping that it isn't still getting in. Behind some of the vents I can see spider webs and leaves trapped there.

Ah, yeah, then if you want to get that kind of stuff out it will be tougher.

if your car has A/C, the evaporator(cooling coil) drain could be clogged (from the above mentioned material) which could prevent the condensation on the cooling coil from draining to the outside of the vehicle and into the vehicle instead

Other than some little rust, scratches and worn decals, the car looks like new now. :)

Meguires #40 worked wonders on the vinyl and bumpers.