An old-fashioned hand wash with a bucket, soap and a lambswool mitt is the best way to remove grime. Be sure to use a soap that’s made specifically for cars rather than dishwashing liquid or laundry soap, which can strip away the car’s protective wax coating and damage the paint.
3. Avoid the heat
Too much heat and intense sun can bake soap right onto your car’s paint and cause streaking, so plan to do your washing when the sun’s not too harsh. Early morning or late in the afternoon is best.
4. Clean the interior first
Pull out the floor mats, whether made of carpet or rubber, and shake, vacuum and—if applicable—scrub with a stiff brush to remove excess dirt that has settled into the fibers or grooves. Vacuum the seats and floor, making sure to push the seats all the way back to remove any hidden debris underneath.