1) improper use of the how-to section. This section is for sharing information, think instruction manuals, on HOW-TO do something. Not HOW-DO I do something. Big difference, common mistake.
2) have you read your owners manual? There is a surprising amount of useful information in that thing.
3) the lines will be a bit scued because of the extreme wide angle lens. My guess is the lines are actually quite accurate but because of the extreme fisheye effect of the lens any minor deviation from straight doesn't show up as well on the camera. Your car may be off by 10 degrees or so but it doesn't show nearly that much off on the camera. Does that make sense?
