1. Clean all the nooks in your car's upholstery using a flat-head screwdriver and a rag. Wrap the rag around the end of the screwdriver, and use it to clean out any dirt and grime stuck in there. Just be gentle. It can rip the vinyl, even with the rag on there.
2. Use a small, foam paintbrush and a can of compressed air to clean your vents. Use the brush first, then blast the vents with some air to finish them off.
3. Clean your grill with dryer sheets instead of a rag. It makes it a little easier to get all the dead bugs off. And it won't scratch the paint.
4. Clean leather seats with Woolite. Spray them with one part Woolite, 10 parts water, and wipe them down or use a toothbrush. With cloth seats, just use carpet cleaner.
5. Clean your headlights with toothpaste. Make sure you use the kind with baking soda in it. They might not look brand new, but it works better than just soap and water.
6. Clean your windshield wipers, and use rubbing alcohol to keep them clean. A lot of people replace them before they really need to. Just wipe them down with hot, soapy water. Then put some rubbing alcohol on there to keep them from streaking.
7. Use soda to clean the corrosion off your car battery. Just unscrew the terminals, and dump some Coke or Pepsi on there. It won't hurt anything. Then scrub the corrosion off with a wire brush, and rinse it with warm water.