DT: EVENFLO BOOSTER SEAT MODEL #2741490, HAD PLACED SON INTO SEAT AND WHILE DRIVING STRUCK POTHOLE AND THE ARM REST ON SEAT PINCHED ARM, LEAVING A BRUISE. THE SEAT ACTUALLY HAS NO ANCHORS OTHER THAN THE CHILD'S WEIGHT, CAN FLIP WITH THE CHILD. REPORTED THIS TO EVENFLO. *AK