A coated fiber mat of improved tear strength upon dividing pieces of the coated mat and the coating is provided. A stent may be molded to form such graspable extensions, or may be cut andor melted or otherwise deformed as part of manufacture. Prior to enabling operation in the non-linear operational mode, the power controller adjusts a value of an error voltage in order to minimize overshoot in the output voltage during the mode switch. Then a legitimate parking sign is displayed and the parking time is downcounted until the allowed time has been completed or until the vehicle leaves the parking space. Into the latter one of two laterally reversed try squares can be inserted selectively from the right or left side.