This is from his twitter feed:
AMIGOS PREPAREN LAS BANDERAS DE MEXICO Y SUS CAMISAS DE SERGIO PEREZ . PORQUE LA FORMULA 1 CORRERA EN MEXICO EN EL AUTODROMO HNOS RODRIGUEZ
Roughly translates to: Friends, prepare your Mexican flags and your Sergio Perez’s tshirts because formula 1 will run in Mexico at the autodromo hermanos rodriguez. You think its true? Its the only source I have so far.