This question got me thinking about launch site selection for missions to Mars. I assumed the optimal launch site inclination would be the one where Mars is due East. Depending on where Mars is in its orbit, this would be at 23.4° ± 0-1.85° (Mars's orbit has an angle of 1.85° wrt the ecliptic). Or would you be better off launching from the equator at an angle of 23.4° ± 0-1.85°?
Or is the solution different altogether?