In a multimedia information and control system for use in an automobile, at least one interface is employed which enables a user to access information concerning the automobile and control vehicle functions in an efficient manner. The conversion unit is adapted for converting a supply voltage of the electrical outlet to at least one of an AC voltage matching a predetermined voltage at the AC bus and a DC voltage matching a predetermined voltage at the DC bus. Each conduit has an obturator movable between open and closed positions and the single reservoir is connected to a further conduit provided with a nozzle situated in the proximity of the surface layer B to be stripped. Thereafter, a compensating implant is selectively implanted to overcompensate the boron previously implanted in the p-type tub.