Has anyone ever experienced this model of car being woken up by RF/radio interference?

It has a battery drain problem but only ever if its parked at the owners house, if its parked at her sons place it can stand for weeks and restart no problem.
i checked parasitic drain at 20ma after 10 mins so im pretty sure this isnt a problem, however one of her neighbours is some kind of amateur radio geek.

Any thoughts gents?

Ed