I think you did the sensable thing. Your operation has rules. I\'m nto sure wether or not you control the rules, but say you do, i am sure you would like to keep things consistant, and expect your employees to follow suit. This makes for a more manageable safe/steady buisniess, ehh?
What terrible things can this disgruntled guy say? \"I came late, i missed my deadline, and now I dont have my car! That damn garage and it\'s curtieious service, and rules.\" \"Hey, I came 2 hours late, and the garage was closed, and i made them re-open, those mechanics are push overs there, and you can get away with hussling them?\" lol
Naw, i dont think either statements are probable, worth saying, or more even worth listening to, from an informed/serious customers point of view.
Sometimes I think exceptions can be made, but basically i find it is usually a safer bet to stick with the rules, especially if the are rules given to you, and following those rules is your job. Secondly, no sensible person should be taking a piss at you for following the established rules of the company. I can understand him getting upset at his predicament.
A steady, or known customer may expect something different, on behalf of his face. This could be a little trickier... i\'d open the garage for the right person.