A head restraint for a motor vehicle has a fixed support part and a movable, prestressed part. A dedicated memory-bypass-enable signal is provided to a memory-bypass-logic circuit of the design during test modes of the simulation. One of the mechanisms is an untrusted mechanism employing the untrusted second machine, while the other is a trusted mechanism performed by the first machine either alone or in combination with a trusted management component that has privileged access to the library. The silane coupling agents are high in heat resistance, such that surfaces modified with these compounds show no decrease in contact angle when exposed to an atmosphere having a temperature of 350\xb0 C. Furthermore, using a cap for covering the distal end of the drug delivery device is disclosed.