Proposed is the design of a rear on-glass antenna for a commercial saloon/sedan. It adapts the mesh-grid structure and proposes the optimum design parameters to maximise matching bandwidth and improve the average vertical gain for the entire FM radio band. The detailed design parameters are determined using the Pareto genetic algorithm with an EM simulation tool. The optimised rear on-glass antenna is built and installed on a commercial saloon/sedan. The measurement results show a half-power matching bandwidth (VSWR <; 5.8) of about 25%, an average bore-sight gain of about -5.43 dBi in the entire FM band, and an average gain of about -3.29 dBi along the azimuth direction.