Slide Seats Forward and Clean Out the Junk
You'll be surprised by what you find behind the seats. We found a lost cell phone, enough pens and pencils to equip a small office, and enough change for several vending machine lunches. Vacuum the seats, remove the mats and vacuum the carpet. Use a brush attachment for the dash and door panels. Don't forget to clean out and vacuum those handy door pockets (another source of buried treasure). Learn how to get the best vacuum for the job.
Deep-Clean Carpet and Upholstery
Use a carpet cleaning machine to get the deep dirt that settles into the fibers of the carpet. (Clean cloth seats this way as well.) It sprays the carpet with a solution of water and cleaner and then sucks the dirt and grime into a reservoir. A machine like this pays for itself after just a few uses. You can also rent one from a rental center or use a spray-on cleaner and a scrub brush instead.