Originally Posted by Mike-in-Orange

Wax is essentially a type of grease. Any dish washing detergent worth a darn will effectively remove grease from your dishes. If it does that well, it will also strip wax from your car.

Regular use of a dishwashing detergent can cause issues for the paint, vinyl and rubber trim, etc over time. But, and this is a big but, if you wax regularly (like after every time you wash with the stuff) and apply a protectant of some sort to all the plastic and rubber trim, you won't have as big a problem as those who wash with Dawn (or similar) every week but never do anything else to their car. And there are a LOT of people who treat their cars this way.

Over time you can literally dry out the paint, which can lead to premature clear coat failure. This assumes you NEVER wax or polish the car, however. I'm just a big fan of "best practices" when it comes to auto maintenance (whether that be mechanical or appearance) so I avoid dish soaps at all costs.

Comments like this though "I just had a bucket with clean water, a rag, and a hose. I put the dish soap directly on the rag and did my car one section at a time" just give me the *******!!!