[tyler durden]

my suggestion

Only works if you keep to the same seat position.

Drive car into position.

Then draw a ink marker line vertically in line with your drivers side rear view mirror.

Then when you drive into the garage, keep an occasional eye on the mirror and stop as soon as you reach the line.

Works fine for me - very cheap and no need to hammer a wood block into the floor. Having said that the wood block idea sounds the most reliable.