Touchless
High-pressure water and detergent, no contact. Safe for a coating and for film. The detergents are strong, so rinse well and skip the "ceramic sealant" or "spray wax" add-on; it leaves a film over the coating that streaks.
Brush and cloth
The brushes carry the grit of every car before you and drag it across yours. On uncoated paint that is where swirls come from. On a coating it is abrasion that wears the coating away, wash by wash. A coating that should last five years can be gone in one.
The warranty angle
Ceramic Pro warranties exclude damage from improper washing, and brush washes are the textbook case. The annual maintenance detail catches early wear, but it cannot keep up with weekly brushes.
The better routine
Pressure washer or hose, foam, a soft mitt where needed, rinse, dry. On a coated car it takes ten to fifteen minutes and there is nothing to scrub. If time is the problem, touchless.
