Do not use dishwashing soap or laundry detergent to clean a car. Dishwashing liquid is ideal for removing grease from your serving trays, but it also removes oil from the paint on your car’s finish. And laundry soap, which contains abrasive agents, can actually scratch the finish of your vehicle. Murphy’s Oil Soap is great for cleaning a car inside and out. Tough on dirt and road grime, it’s surprisingly gentle on your vehicle’s finish. Baking soda works well to remove tar and anything sticky from a car’s finish.