During the winter months, in many locations, we keep the windows rolled up for the season. Not much fresh air flows. The vehicle interior develops a musty smell which becomes distressingly apparent when the warmer weather arrives. Snow brought in on boots and shoes collects in the carpet causing sogginess. When the vehicle is put away, it refreezes and remains relatively inert. When the milder season arrives, the carpet-thaw occurs. If the dampness is not rectified, mold spreads.
Clutter is a frequent companion, as well. Some of us tote around an extra jacket, emergency blanket, tools, and other minutia that we don't accumulate at other times of the year. This clutter can conceal crud and retain moisture which would likely contribute to the mustiness and mold already mentioned. In the event of a collision or sudden stop, loose items can cause injury.
The surfaces of a passenger transportation vehicle may be more biologically contaminated than a public restroom. It's true. Don't let it happen to you!
Adequate cleanup can be accomplished with just a few things. 50,000 chemicals are not really necessary. Being confined with fumes from dashboard-shiner-upper and carpet-smells-gooder-mist could make you feel pretty crummy and you'd never make the connection. The fumes may be present long after the job is done. I suggest you keep it simple.
The list of basic items needed:
1. Bag for removing debris (fast food wrappers, beverage containers, bottle caps, and so forth)
2. Wet&Dry vacuum cleaner
3. Paper towels (sponges aren't a great idea because biological life forms breed in the pores - you might end up wiping on bad stuff)
4. Disinfecting multi-surface cleaner (you might be tempted to use multiple products, but chemical interaction is worth avoiding)
5. Time (it took me about 30 minutes)
Optional items that are helpful for meticulous people:
a. Cotton Swabs (for the louvres on the dash vents and the recesses of handles)
b. Old Tooth Brush (some surfaces have a texture that may elude paper towel)
c. Plastic Scrubbie (not the abrasive kind)
d. Stiff Bristled Scrub Brush (for loosening up sticky carpet critters)
e. Tweezers or Hemostats (to pull coins and stuff out of tight crevices)