you may be able to tell just by looking at the mounted spring whether or not they were mounted correctly. but the front wheelwell will always be a little gapped, but thats because of the fender size. take a look at the car form the side...see how much higher the front wheelwell is than the back. good luck filling it though, im lowered almost 3 inches on 19" wheels and i still count at least an inch of gap in front.
