When I bought a new Ford Escape in 2020, I vowed to keep it shiny and clean, unlike my old Toyota that I traded in with 220,000 miles. That car was silver and didn’t show dirt easily. But my new car was the perfect shade of red, so signing up for a car wash membership ensured that I’d always be riding in shiny style. I’d been to all three full-service car washes in my neighborhood over the years, typically getting the full inside and outside treatment before I made a road trip. The car wash down...