What I find about some of us engineers, car DIYers etc. is that we can so often put the so called dealer professionals to shame. We may take a little longer but that is because we research, take care and pride in our work.
I recently had my drive shafts replaced. I did check with the parts dept. that they had the specified parts the technician requested in stock and then allowed my car to be booked in.
On the due day, service reception asked if I was OK with the car being with them all day. I said no problem, even qualified this saying please keep the car overnight or longer if you need to order unforseen parts. etc.
I got my car back but the innner CV joint boots were secured with standard Jubilee clips (nice lumps of off center metal to add imballance).
Drive shaft vibration / slack was the reason they were replacing them in the first place.
Before you ask, no I've not gone back to complain. When I sevice my car when it is out of warranty this coming December, it will take me no more than about 30 minutes to put the propper compression bands on. I have to pliers and the parts will only cost me a few quid.
Having said this it makes me wonder what grease was put into the inner CV joints? Propper CV Moly grease or what ever they happended to have lying around.
It makes you wonder if you can trust garage and service team other than an F1 or WRC pit team.
The real rub is that when you pick up on something a garage has done wrong, you then become more concerned that they will perform poorly again. So you check everything they do, even to the point trying to prevent problems by concerned questions before they do a job. This leads to you being a pain, if not in their eyes then in your own eyes.