When I was a kid we lived across the street from a fellow who had what I thought was an uncanny ability to park his cars in his garage with perfect accuracy every time. There was always room to open all car doors without striking the other car and there was always room to get in and out of both cars from either side. His garage wasn't any larger than a standard two car garage and he also had some of the extras in there that many people do, such as a snow blower, a chest freezer and of course the lawnmower and some lawn tools. So how did this fellow get his cars situated in perfect fashion as a matter of course? I went one day to find the answer.
What our neighbor had done was to park his cars in the garage one day in the exact position that he wanted them. Then he took two tennis balls, threaded each one on a string line and hung them both from the garage rafters
in position so each one would just touch the windshield of each car right in front of the rear view mirror. From then on, all he and his wife needed to do was ease in either car until the tennis ball came to rest on the windshield, in front of the rear view mirror. Presto! A perfect parking job every time.
Check out 17 good uses
for a Tennis ball, from DIY Life's own Dan Chilton.