I claim the ornamental design for motor vehicle radio antenna, as shown and described.
FIG. 1 is a front elevational view of a motor vehicle radio antenna illustrating my new design, it being understood that the shaft is foreshortened to fit on the drawing sheet but has the length shown in FIG. 6;
FIG. 2 is a right side elevational view thereof;
FIG. 3 is a left side elevational view thereof;
FIG. 4 is a top plan view thereof;
FIG. 5 is a bottom plan view thereof; and,
FIG. 6 is a perspective view thereof, at a reduced scale.