1. Use a cheap foam brush or paint brush to dust between the AC vents.
2. Vacuum up the dust as you brush it off, so it doesn't immediately settle somewhere else in the car.
3. The vacuum+brush duster combo also works to clean all your car's knobs and buttons.
4. Remove and replace your cabin's air filter to get rid of stinky smells.
5. Get all of the trash out from every nook and cranny.
6. Use a Magic Eraser to scrub gross sticky things off of vinyl and leather.
Gently rub dried on gunk with the Magic Eraser — don't rub too hard, because you don't want to damage the fabric. From here.
7. If dirt has embedded itself in the textures of your vinyl, some detail scrubbing with a toothbrush may be necessary.
8. Use olive oil to condition and polish the leather on your dashboard.
9. Banish animal hair from your upholstery with a spray bottle of water and a squeegee.
10. Use a fine-bristled brush (like a toothbrush) to get dirt and crumbs out from the seams of your seat cushions.
11. Use paper and an iron to remove melted wax (like crayons) from your upholstery.
12. Shampoo the seats in your car with diluted all-purpose cleaner, a sponge or scrub brush, and washcloths.
13. Spray your dirty floor mats with stain remover and throw them in the washing machine.
14. Or, scrub them with a DIY upholstery cleaner.
15. Enlist a lint roller, bristle brush, toothbrush, dish soap, steam cleaner, and baking soda if you need to clean a kiddo's car seat.
This is not an easy process, but you can do it! See the full tutorial here.
16. When everything's fresh and clean, keep it smelling that way with a baking soda air freshener.
Get the how-to here.