Originally Posted by junkman
String from the ceiling that hits the windshield is what I use.
Just attach a tennis ball to the end of the string to let it hit the inspection sticker (or registration sticker, or something you put in the window of the vehicle) when you are positioned correctly in the garage. I've used this on every vehicle I've had (including motorcycles) for years. Never fails to correctly position the vehicle in the garage.
First, get the vehicle positioned exactly where you want it in the garage. Next, take a length of string and the attached tennis ball (I use a cup hook screwed into the ball) and, from a ladder, hold the string contraption directly over the portion of the windshield that you want to use as your position marker. Mark the ceiling, screw the string into the mark, fine tune the string length, and then fergeddabout parking problems.
Cost: string and tennis ball, although if you have a dog you probably already have a tennis ball ;-)