What a tunnel cannot reach
A tunnel wash does a fine job on the dirt that sits on top of paint. It is not built to lift what has bonded to it. Tar thrown up from fresh road work, iron fallout that shows as tiny orange specks, and road debris baked on behind the wheels all ride through the foam and come out the other side.
That is the gap the detail shop fills. If your paint feels rough after a clean wash, run a clean hand across the hood and you will usually feel it. The detail team takes that bonded layer off by hand, which is work no conveyor can do.
Route 146 is not gentle on a car, and New England winters make it worse. A detail every so often is how a daily driver stays smooth under the wax.
