I have not cut off the bottom of my dust shield, but removed them. Overall I like these, at worst they provide a nice source of air over the LCA boot with the Shield Removed. With the dust shields removed, a GOOD brake fluid (I use React) and high temp pads (EBC Yellow/Summer Motorcraft) I am quite content with the setup for fast track days of 20-30min sessions of hard braking no smoke or soft pedals.