This paper proposes a transparent glass quartz antenna for 5G-millimeter-wave-connected vehicles and clarifies the characteristics of signal reception when the glass antennas are placed on the windows of a vehicle traveling in an urban environment. Synthetic fused quartz is a material particularly suited for millimeter-wave devices owing to its excellent low transmission loss. Realizing synthetic fused quartz devices requires accurate micromachining technology specialized for the material coupled with the material technology. This paper presents a transparent antenna comprising a thin mesh pattern on a quartz substrate for installation on a vehicle window. A comparison of distributed transparent antennas and an omnidirectional antenna shows that the relative received power of the distributed antenna system is higher than that of the omnidirectional antenna. In addition, results show that the power received is similar when using vertically and horizontally polarized antennas. The design is verified in a field test using transparent antennas on the windows of a real vehicle.