Might as well have another .02 thrown in before you take a few day's off.
We are a G.M dealer that is small but potent. Our D.P will re-purpose an employee before they are told to hit the brick's. With that being said, I am the second parts manager in 22 years of the current ownership. I replaced a retired manager. I am on my 3rd service manager in just under my 4 year tenure. The current service manager is a re-purposed sales flunky. (he MAY make it)
We had a similar situation with a past writer, that always had a better way to do EVERYthing. Always takes a lunch. Always leaves at 5:01. Blah blah blah.
Quick background on the writer.He is a washed out salesman, that was moved to the service desk. Ex-navy. Ex-plant middle management. (plant closed) ALWAYS right. Never made a mistake (in his mind) ALWAYS takes a lunch. ALWAYS left at 5:01. ALWAYS tried to find an easier way to do EVERYthing. If he wrote a mechanical estimate, sold it, and figured the ticket, it was always off. The first thing out of his mouth was "parts are to high". He would toddle to parts and expect a discount to "level the estimate". The writing was on the wall.
I reminded him that the labor rate was $100 an hour, with a $20-ish cost. That's a 500 percent mark-up. At best, I am working on a 100% margin AND I don't turn around and give 50% of that, back to the service department. It didn't sink in. He would rather worry about R.O percentage and labor per R.O, (a $100 piece of his check) than make labor AND parts gross, that would far out way his piddly $100 bonus.
Now that the history lesson is done, he ended up being his own worst enemy. Popped off to many times to the wrong people, and he was told to GTFO.
I have wrenched, wrote service, fixed op managed, and the best, parts managed for 35 years. 32 years of it in a management position.
My advice to you is, if he is worth keeping, you/someone better get a handle on him. If not, his attitude will splash all over your good people, and the store will suffer. It's hard, if not impossible, to get everyone on the same page AND with the same attitude. Money usually helps, but the environment will make as much a difference as the money.
Even though you got about .50 worth, I feel your pain and frustration. Someone needs to get on this pretty quick. It will only get worse.