The 13th of November 2010 I had some fantastic signals from a few mexicans and one of them that I heard for the first time this morning was XERFR Radio Fórmula -970 with its TOH ID as "escuche Radio Fórmula, Groupo fórmula presente..." . This is their Primera Cadena of three channels. A few days later, 17th of Nov. I also got nice call ID of XEAI R Fórmula Tercera Cadena -1470 and XEDF R Fórmula Segunda Cadena -1500. These station are the core of a big network of stations in Mexico. A fourth "cadena" is also established by stations in US.
I got a mail today from José Pablo Cabello, VP Fórmula Digital y Comercial verifying all three stations.