A genuine deep clean, not a longer wipe-down
The difference between Premium and the tiers below it is depth. A vacuum lifts what is loose and a shampoo lifts what is near the surface, but years of use push dirt down into the weave of carpets and seat fabric where neither reaches. Premium works those fibres properly so the dirt comes up and out rather than being pushed around. The same applies to the parts of a cabin people stop noticing: air vents, seat rails, seatbelt webbing, the seams either side of the console, the grab handles. Individually small, collectively the reason a car still feels tired after a clean.
