I possess a windy gun(same as used by garages)and its residing at the back of the shed as its unable to compete with a wheelbrace and 6ft of scaffold tube,bit inconveinient to carry round in the boot for roadside repairs but after a trip to a garage to have tyres changed I always go round and slacken then torque the nuts back up so I can actually undo them if ever needed.I started doing this after a garage had tightened the nuts so tight I couldnt undo them when I collected a puncture on the M6,and had to resort to calling the (free with my insurance renewal) AA/RAC (or whatever the actual recoveryman was called) and wait their assistance.I also know several of the guys who work at the tyre depot personally,and its kind of a "works joke" between them to see just how tight they can get the nuts without shearing off a stud.When the Boss started receiving heaps of complaints though,they were all issued a memo stating they had to use a torque-wrench(which just meant they now had a means to measure reasonably accurately how tight they'd got the nuts before a stud sheared)I now use a much nearer tyre services as he works alone(nobody to compete against)and he also adds a smear of grease to the studs because even the tiniest bit of rust can make a nut lock so tight a scaffold tube on the wheelbrace results in the stud shearing anyways.
as it was parked next to my car and I happened to have my camera with me. The owner saw the flash and got out of his car to 'see if I was looking for trouble'. He changed his mind when I got out as well -I'm not exactly a 9 stone weakling, even without my hat- but when I pointed out the snapped stud he just shrugged and said there were still 3 more nuts holding the wheel on. I felt like takeing hold of one of his ears and making him stand in a corner!