the Vienna Convention on Diplomatic Relations sez:

"Article 38 (2). Other members of the staff of the mission and private servants who are nationals of or permanently resident in the receiving State shall enjoy privileges and immunities only to the extent admitted by the receiving State. However, the receiving State must exercise its jurisdiction over those persons in such a manner as not to interfere unduly with the performance of the functions of the mission."

in general, i guess the pinoy drivers are not immune to traffic rules unless they are performing duties in connection to their "work" as members of the diplomatic household