Dealerships are both a completely separate legal entity from the manufacturer and they have a very strong interest in not handing over a defective car to the cu

Dealerships are both a completely separate legal entity from the manufacturer and they have a very strong interest in not handing over a defective car to the customer because they're closes to the customer. They are also required to conduct what's called a PDI - Pre Delivery Inspection - before the customer sees or touches the car. The car is prepped for sale, and this includes a number of things. Sometimes cars have spacers installed in the suspension. Someone plugs in a diagnostic tool and tells the car's control modules that the car is no longer being stored/shipped, so it can enable all the stuff slowly drains the battery like memory settings, keyless ignition RF transmission, alarm sensors, etc. There's also a cosmetic inspection, where any defects in the paint are taken care of by the dealer's in-house detailing/car prep staff. A big part of the PDI is going over everything safety related and making sure that nothing happened to the car as part of it being shipped. That includes a test-drive. Usually half an hour or so at a variety of speeds, where the test-driver makes sure every single part works. I assure you, the person doing the PDI would notice a missing brake pad, even if the dealership mechanic who does the mechanical PDI somehow missed "there's a brake pad completely missing."