I wondered the same thing when I got my first. The answer is no. As long as you stick to soft materials like sponges, cloths, and plastic when scrubbing your car, it won’t cause any problems. Wash it every day if you’d like.
It is, however, important to use proper equipment and technique. For example, while your sponge won’t scratch the paint, sand and other types of grime stuck to your car might scratch the paint if you are not careful. Make sure to rinse the car off thoroughly with water before you start scrubbing. It’s also a good idea to get stuck with soaps and cleaning products made for cars, as regular kitchen supplies might damage the paint.
The use of protective coatings on cars is also becoming more popular — check the clear bra Denver page of Pro-Tech Auto Shield & Nano Coatings if you haven’t heard of these — and harsh cleaning products can damage those as well.