[duke]

Getting the body on straight is pretty critical and mine from the factory was offset almost 1". There are a number of other B&B posts on the subject. I aligned the body fender lips to the tires left/right and front/back. The mounting screws under the door impact how the door gaps fit. You can push and pull the body almost a 1/2" to get the doors to align.
If you are triming your trunk, and hood be careful to center the hood scoop and license light BEFORE you do any triming. Otherwise if you cut to much from one side they will be offset.
Good Luck.