[wakawaka28]

Generally I agree, but only the dealers and manufacturer have all the technical data, software, and access to parts for these cars. They would not take telling a customer the job is infeasible lightly, especially if they have a warranty. They would probably send the customer to a different repair shop in their network if that was possible and necessary.

[bcrl]

Your faith in dealerships is unreasonably high. Based on my experiences maintaining a fleet of trucks for my company in addition to my personal vehicles, there are most certainly dealerships / mechanics that are incompetent and unable to fix certain problems within a reasonable amount of time. Their mechanics are not magicians, and they vary in skill level significantly. Sometimes a quick 5 minutes spent on the internet will find a solution for a problem that the dealer's mechanics are clueless about, as was the case with the anti-theft lockout on the Alero I had. The stand-pipe issue on one of the older diesel trucks took the mechanic $3k worth of time to diagnose and fix, but once we knew about it, we found out that the issue was quite common for engines of that vintage (and we later found out that the other stand pipe in the engine had already been replaced by another mechanic prior to our purchase of that truck).

Other times a mechanic shows a degree of cleverness that makes them well worth compensating them for the time, like using an infrared camera app on their phone to find a wiring harness short in a minute rather than spending hours crawling around the chassis.