Anyone with more money than time who just wants their car fixed and is willing to pay to have it done correctly. A not so great customer will ask why you couldn't just reuse the old oil, and if he really needs brand new spark plugs, can't you find good used ones?

From what, the customer or mechanic standpoint? From a mechanic standpoint, I'd think a great customer is one who agrees with everything the mechanic says, and orders all work done, as suggested by said mechanic, particularly when boat payments are due. Also, said customer would not argue or complain about anything, and gladly hand over blank check after blank check.

From a customer standpoint, a good customer, I guess, is one who knows what he/she is talking about, and is firm, yet polite when pointing out various services are unnecessary or unneeded, but doesn't look at the mechanic as someone who is only trying to rip them off (unless, of course, the mechanic is... unfortunately an all too common occurrence.)

I knew a guy who talked at a dealer for so long that they refused to change the cracked head on his car. They couldn't deal with two cracked heads at once. I'm a great customer as soon as I pay up and leave. I am willing to work with the system that's available. I know that Sears is the most disjointed place right now, headquarters puts stuff on sale that the local store doesn't stock. My parts came in after the expected week of waiting but they were 50% off. I'm planning to install the parts in three to six weeks. I'm happy and they make two dollars. Perfect world! Some other place sells me a wrong left rear view mirror so I drill new holes and install it, then order its twin for the other side. Better than paying a dealer for the right (correct) one. When I break another one I will know the part number but will probably roll the dice again. If everybody hired good help I would have been unemployed for the last forty years.

One who expects reasonable prices and service. They must understand that on any specific day, things may not work out as expected, but they should not work out poorly every day. They should listen to the professional, just as the mechanic should listen to them. They should be willing to pay a fair price just as the professional should be charging a fair price. They should not be trying to second guess the professional.

This is the same at the grocery store, photo studio, garage, or doctor's office.

In general an honest, competant, and fair mechanic makes for a great customer.

And one who remembers that when a customer brings in a broken car he/she is already in the process of having a bad day....and makes allowance for that.

A great customer is a loyal one, almost a friend, who trusts the repair facility to do the proper work for a fair price in a reasonable time. The great customer will spend time with the owner and mechanics discussing the needed repairs and obtain an estimate. The customer will then leave the repairs to the shop and depart to await the call to come pick up the vehicle. If this process is repeated, and the customer is pleased with all aspects of the experience, then the customer should recommend the shop to all who inquire about repairs to their respective vehicles. The customer should also tell the repair shop owner that business is being referred to him. This creates a give-and-take situation wherein both parties gain from the experience. It doesn't hurt to drop off a gift around the holidays.

Which one is supposed to drop off the gift?

An honest, fair, and competant shop is a gift all year around. A fair, understanding, paying customer is a gift all year around. Perhaps they should swap gifts! Naw, nevermind.

A great customer is someone who is willing to take the time to make sure the mecahnic knows what their concern is, not just drop the car off and say it isn't runnung right, or it is noisy. Take a ride with the mechanic or service advisor and make sure you both know what the other is talking about. Then, do not have unreasonable expectations about what it will cost to fix your car. We all know car repair is expensive, be prepared to pay for the repairs you have requested.

If the great customer is shorter, that person will move the seat back so the taller mechanic (if appropriate) can fit behind the wheel. Also, a great customer has his/her car free from trash, at least in the front seats and bring the car in reasonable clean, esp in winter.
A great mechanic will realize that the owner knows what a "strange" is MORE that they do and not dismiss such seamingly unimportant concerns.

I'd suggest that a good customer with a problem to solve might be one who -if s/he is automotively challenged, like I- would come in with a set of symptoms and explain that s/he is not trying to diagnose the problem but only presenting the symptoms, and if I had an idea, might say something like: "Well, if I knew what I was talking about I would think it behaves like the starting motor is failing", "it sounds like the kind of metal/metal screech of a belt tensioner headed south". That, or, lacking any idea of the source, I'd fall back on tentatively proposing the old reliable 'sympathetic vibration' or 'loose catalytic heat shield' which seems to be the answer to all otherwise-unsolvable noise problems on CarTalk. c.a.

Do mechanics like to get homemade baked goods as an additional thanks? I've thought of giving some to mine, especially when they give me really good service - but some people don't really like to get food from strangers. Any thoughts? Are sweets like brownies/muffins preferred to homemade bread?