Why does my car shake and rattle when I depress the brake pedal at 50 miles an hour and faster the front end seems to Rattle like through the pedal and through the steering wheel

Front brake rotors have a excessive runout, warped... Possibly from incorrect lug nut torque.

Hi excessive run out means the brake rotors are not flat or true, you may have gotten a defective set of rotors. If your rack & pinion is bad that could also cause the front end to shake. If you are still having problems we will do a no charge brake inspection and inspect your rack & pinion for you also. Thank you Bryan Gossel BG Automotive 970-484-1443