auto lock after shutdown/walk away

greetings,
just got my 2011- lovin' it!!- and have exhaustively poured over the threads to find this feature; had it on my insight (via honda's own alarm system) for 10 yrs and dearly miss it, but cannot find it anywhere else. there was a tantalizingly close thread 5 yrs ago by naterprius, but it seems to have fizzled. i'm good w electronics and could build it if someone could point me towards the right design (good w construction, not so much w designing)
any chance anyone knows where the design for this module might be floating around out there??
thanks
everette