WAS IN AN ACCIDENT ON A GRAVEL ROAD. QUICK 90 DEGREE TURN IN ROAD IN FAMILIAR ROAD, NO SIGNS WARNING OF TURN WERE POSTED. BRAKED FOR TURN. DUE TO GRAVEL VEHICLE SLID. WENT OFF ON LEFT SIDE AREA (TREE LINE) NEXT TO ROAD. HIT TREE ON FRONT PASSENGER'S SIDE RIGHT NEXT TO CENTER. AIR BAGS DID NOT DEPLOY. CONCERNED ON WHETHER THIS IS DUE TO MANUFACTURE DEFECT OR USED CAR DEALER NEGLIGENCE.*AK