a motor vehicle windshield is formed with a transparent vapor - deposited metal coating for windshield heating and with an antenna for radio reception . preferably , the metal coating is connected to an inner conductor of a coaxial cable leading to the radio receiver , while the outer conductor of the coaxial cable is connected to chassis or ground potential . a slot in the metal coating is dimensioned to have a length of some harmonic of one wavelength in the fm frequency band , a width smaller than a half wavelength , and a minimum spacing a from the supply buses on each side of the windshield .