Use interior cleaning when contamination lies inside the weather seals or within materials that cannot be openly rinsed: upholstery, carpet, foam, controls, screens, headliners, belts, vents, and crevices. Vacuum capture, metered chemistry, towel transfer, compatible extraction, airflow, and time control soil without flooding hidden construction.
Car wash equipment belongs where exterior surfaces, water supply, spray energy, and drainage can transport broad contamination safely. Pressure, high flow, wheel tools, underbody rinsing, and wash-bay systems are not shortcuts for cabins. The decision should follow soil location, moisture path, recovery, electronics, adhesives, and site capability.