The Classics;

Monte
Sweden
Mexico
Italy
Portugal
Finland
Greece
Japan

Alternating asfalt rallys could be;
Croatia and Corsica
Germany and Ypres
Spain and Ireland

Gravel could be
Latvia and Estonia
New Zealand and Australia
Argentina and chili
Jordan and Saudi Arabia
Turkey and Cyprus

Just my thoughts, probably never will happen, but i think most rallys could benefit from this system.