What you fail to mention is most mechanics are basically paid to be speed workers. Meaning that jobs are paid in number of hours expected, not what it takes to do the job. There's also two labor guides, one for warranty and one for non-warranty. An engine swap w/o warranty may pay 10 hours, in the warranty book it's likely paying only 6 hours. The system put in place by someone that doesn't work on cars is driving these guys to find as many shortcuts and methods to do work faster than the engineers say it can be done.
I've yet to see anyone put a shield on a 3800 that stops oil from burning off the manifold. If you have problems, call the GM 800 number and be a reasonable person.
