The sub frames do require quite a bit of trial and error grind and fit and grind again and fit and grind again to fit the floor nice . it took me approx 8 hours of this to fit mine to the floor , they don't tell you that when you buy them . But since i was welding them in myself i just stuck with it. They will look nice .
When your paying someone who really only cares about what he is going to get paid on the job and is trying to get them done as fast as possible you have a problem .