The body count in this episode (3) is greater than the combined body count of both movies (2) (Abraham Lincoln and Thomas Gates excluded)
There is a brief outside shot of Mexico City streets but the location of the shot is actually Centro histórico de Quito, Ecuador and not Mexico City. In the background you can see the statue of El Panecillo Hill.
Cras est nostrum is a variation of the Latin phrase cras es noster meaning 'tomorrow, be ours' or roughly 'the future is ours' which is also the motto of San Jacinto College that has multiple locations in Texas. It appears to be the name of the mysterious group that Billie works for(with)