A good or bad customer? The good customer is just like the good counter guy. Knowledgable about his own stuff and able to help the counter guy, with patience, when the computer won't spit out the right info. And it's not just on antiques or muscle like we're on here to share, but on everything. For instance: "Sorry, Robert, but the computer is showing that part as being unavailable for this car..." Well, then let's see, I know they used this same part on the a different model and a different year, let's try this one..."Yup, it's coming up as a good listing on that." Or, "well, if it's coming up no good let's try the part number and see if we get something off that."
The bad customer? The guy who gets billegerent about every little thing because he expects everyone but himself to be an expert on his own car.