My son is in management with a fairly large construction company. One of his jobs is overseeing repairs done to their pickup fleet. He just had a bill for $2K to repair a "slams violently when placed in drive or reverse" situation on a newer truck. The dealer failed to diagnose or repair the thing, but billed for the $2k. He takes the truck to his in-house heavy truck shop, and asks a real truck mechanic to take a look. A few minutes later, he climbs under the thing and his truck mechanic shows him a driveshaft that is about to fall out, since a U-joint is in it's last stages of disintegrating.
He has an ecoboost, under warranty, with a strange engine whistle. He researched and found that it was broken exhaust studs. The service writer tells him that "it's fine, the tech. says it's normal, since his personal truck makes the same noise" My kid tells him the truck stays at the dealer until they have a competent mechanic check the studs, and asks "when did the fact that a tech.is too dumb to figure out what broken head studs are become a benchmark for how a new truck should sound and run?" They find broken studs and replace them. He picks the truck up, and it has the same whistle. He circles the lot and asks WTH? The service writer tells him that they only did one side, since that side was broke. Apparently a test drive, and looking at the other side of the engine was too much to ask. My kid grabs the keys for the new Expedition he had as a loaner, and tells them to keep trying, as he continues to put a thousand miles a week on their fancy SUV.