1. Get Off The Pavement
If you change nothing else in your car-care routine, park your vehicle on a flat, permeable surface (lawn, gravel, or dirt) rather than on pavement. Natural microbes in grass, soil, and dirt work as natural filters, breaking down some of the nasty compounds in your wash water and preventing them from running off into the nearest storm drain.
2: Do It Yourself
For those who really relish the hands-on experience of shining up their rides, head to a self-service car wash where the runoff water is captured and sent to a treatment plant. This is often the greenest—and least expensive—option, using about 15 gallons of water. Plus, you can use your own biodegradable dish soap. Those larger commercial drive-through systems use more water than self-service, about 35 to 50 gallons, depending on the type, but that's still much less than if you washed it at home. Just be sure to pass up the extra treatments and waxes (which are unlikely to offer eco-options) and stick with a plain-Jane wash.
3. Go Waterless
While buckets, oversized sponges, a long hose, and soaked clothing are part of DIY car wash tradition, you really don't need any of those things to give your car, truck, motorcycle, boat, or plane—don't laugh, I've washed more small planes than I have cars over the years—a clean, green shine. There are a number of premade, ecofriendly waterless car wash products available (one we've tested and like is EcoTouch). Or you can just grab your spray bottle of home-brewed window or Almost Everything cleaner and at least two soft, absorbent, clean rags or microfiber cleaning cloths (more if your car is really grubby). Read the directions if you're using a commercial product. But if using homemade cleaners, mist a small area with the spray-on cleaner, wipe the product and dirt off that area with the first cloth, and then buff the area with the second dry cloth. Replace the cloths as needed.
4. Use Vinegar
Loosen baked-on bugs first by spraying with cleaner and letting it sit for a couple of minutes before wiping, or use a nonabrasive kitchen scrubby to loosen them. You can also soak a cloth with vinegar or denatured alcohol and use it to soak and rub off dried-on bugs. Rinse with water and rewax the area (vinegar if left on can strip a car's finish).
5. Raid Your Pantry
For tree sap or tar on the exterior, dab some peanut butter or solid shortening on the goo, let it sit for a minute or two, and wipe it off with a separate cloth before using your cleaner. Repeat a few times if necessary. Denatured alcohol will also remove tar and sap.
6. Score A Squeegee
Wash the windows inside and out, and while you're at it, wash the mirrors and the headlight and taillight glass. Follow my tips for using a squeegee to get the cleanest windows in the parking lot. Hint: Roll the door windows down slightly and clean the top edge first, then roll them up and clean the remainder of the window. And, since we're heading into cool, dewy mornings and foggy fall evenings, apply an ecofriendly antifogging treatment to the windshield and mirrors. One I like is Doctor Klear.
7. Sprinkle On A Natrual Deodorizer
Vacuum the interior using a crevice tool to get into the cracks and crannies, and freshen up your upholstery if it needs it, by sprinkling some odor-absorbing dry baking soda onto the seats, and letting it sit for 30 minutes to two hours before vacuuming it up.
8. Wax On Organically
Make your own protectant by mixing one part fresh lemon juice with two parts olive oil in a small bowl. Dab a small amount onto a soft cloth and rub it over the dashboard and other plastic and vinyl surfaces (but not the pedals, the steering wheel, or other surfaces that shouldn't be slippery). Use a retired toothbrush to work the solution into cracks and remove trapped dust and gunk. Buff with a second dry, clean cloth; the mixture will leave a soft shine and a pleasant smell. Discard any unused mixture, or store it in a clearly marked container in the fridge.
DIY Car Wax
Most new cars have highly resistant shiny protective finishes, but if you feel the need to shine, or if you used vinegar to get bugs or other gunk off the body, you can revive the shine using a batch of your own green car wax.
1 cup linseed oil
4 tablespoons pure carnauba wax (sold in auto parts stores)
2 tablespoons beeswax
½ cup apple cider vinegar
1. Place ingredients in an old double boiler or in a tin can set in a saucepan of hot water. Heat over low heat, stirring frequently, until the waxes melt and disappear. Pour into a shallow container with a lid and allow to cool.
2. Wax your car in the shade so the metal stays reasonably cool, and work on a small section at a time. Apply a small dab to a clean surface with a soft cloth, rubbing in a circular motion; then buff with a clean cloth.