I'd use either #9 or MPPC and go with a lighter glaze after them or
Meguiars #20 then top with #16 if you want a wetter look (assuming you prefer to stay with
Meguiars).
Bret is right, 3-4 times a year for the average car is fine. Washing your car is more important since dirt,
grime, bird bombs, sap, etc are tough on the wax and paint if you let them sit for weeks on end. Wash and vacuum regularly! Maintain the shine with a quick detailer.