If you want to annoy a mechanic:
-spit chewing tobacco on the floor of your combine or tractor's cab, and then ask him to make repairs that require him to lay on that floor. (If you think people don't spit chew juice on their floor, ride with me for a week.)
-permanently bolt tool boxes or storage bins to, or in front of, shields, doors, etc. that need to be opened for regular maintenance or common repairs.
-"borrow" tools from the mechanic's service truck to do maintenance or repairs on another part of the machine, while he's working on the initial repairs. Extra points are deducted if the tools aren't returned.
-expect the mechanic to make repairs to aftermarket parts or systems, and then complain because he doesn't know the specifications or calibrations for the oddball, off-breed systems or components.
-disparage, complain and bad-mouth the dealership, with the expectation that the mechanic will return to the store and immediately trot into the headman's office and relay the complaint.
-comment that the neighbor across the fence, with a competitive brand of machine, "...never seems to have this many breakdowns."
-call the mechanic at 7 a.m. on Sunday with expectations of immediate repairs. Some mechanics offer that sort of service. Many don't.
-did I mention chewing tobacco on the floor of the cab? Also, spilled pop cans, spilled beer cans, the remnants of yesterday's sandwich (with mayo), GummiBears, and that sticky, slimy stuff that's spilled under the armrest.