Personally I think the spoiler shown in the first post is still about 4" too narrow and is not 'covering' the front wheels. 1-2" lower would look better too imo.
The spoiler I have is about the same distance off the ground as yours. Also, my fenders are narrower than the front tires making a spoiler wider than them impractical. I might be able to go about 2" wider if I could find a different one that fit...maybe...