Apparatus and methods for preventing penetration of vehicles by causing the guardrail extruder terminal to contact and engage the frame or chassis of vehicles in a collision. In preferred embodiments, a guardrail extruder terminal end treatment is adapted for improved operation during impacts by attachment of a frame catcher penetration guard. The frame catcher adaptation extends below the usual lower edge of the impact head of the guardrail extruder terminal design in order to contact portions of the chassis of a vehicle during an impact at the guardrail end. In several embodiments, the impact head of a guardrail extruder terminal includes a substantially rigid downwardly extending portion which presents an expanded contact area, the location of which approximates the location of a portion of the vehicle's chassis. The frame catcher devices may be retrofitted onto existing guardrail extruder terminal impact heads.