I have two of the "single-car garage" kits (says ~250sq. ft. each) for my roughly 480sq. ft. garage, so I should be able to lay it on fairly well. My garage is separated into four "squares" by the indented lines. I'm sure there is a technical term for them that I am forgetting right now. But anyway, I am planning on doing one "square" at a time, and treating each as its own individual floor, so I should not have any of the aforementioned gloss differences in overlapping, etc. Hopefully.
Pics tomorrow!