WHILE BACKING UP, IMAGE OF REAR VIEW AND OVERHEAD CAMERA FROZE. IMAGE SHOWED A CLEAR AREA BEHIND CAR AND I CONTINUED TO BACK. I BACKED SEVERAL MORE YARDS AND HIT THICK UNDERBRUSH BEFORE I REALIZED THE IMAGE WAS NOT ACCURATE. I CUT OFF CAR AND RESTARTED AND IMAGE STILL FROZE. THERE WAS NO DAMAGE FROM CONTACT WITH BRUSH BUT THERE WAS A LARGE TREE WITHIN 2 FEET OF THE CAR'S REAR.