Thats some freaky shit!
Id say the jackets were just to cover up being there and they were checkin the cars out so they know when youre there or not .
i would suggest beefin up ya security and actually taking out one of your
spark plug leads for a while or something just as easy ,THAT WILL **** EM
and you and your dad have learned a lesson ,IF ANYONE COMES TO YOUR DOOR YOU DONT KNOW - TELL EM NOTHING