Has an Police/experts suggested a practical counter-measures to this sort of crime?
I know some here have said "leave your keys near a window in the house" but... taking that to its logical conclusion, the least possible damage would be to leave a spare key on the passenger seat and then at least they only break (now their own) car window and leave you and your family in peace... Yeah I'm being a bit tongue in cheek but...
PS to the OP, sorry to hear you had this crappy thing happen to you 
wasn't far off what they said to be honest...
if they couldn't see the key, they have been entering into properties to find them, as i was no 8 on a list of vehicles stolen in the past 10 days in the area...
again, if vehicles had trackers as standard, it would of helped.
i remember the days when we had keypad on the dash to enter pin numbers before you could start the car PITA but sort of worked.
Agree with the key on the seat option as well....
Having not really slept for the past 2 nights, been awake on high alert, have had time to think more about things whilst also playing back the sound of the smashing glass over in my head.
I'm more P1ssd they targeted me.. they got away with it, its like its 1 - 0 to the criminal. take the car, that can be replaced. But to leave me and the misses in fear in our own home, that's the kicker!
then there's the inconvenience...spent 30 mins on the phone to the insurance assessors yesterday, felt like it was my fault at the end of the conversation...then i had the glaziers round to board up my window, lock smith left at 9:30p, after changing all the locks..home insurance assessor round to video the property, fill out forms, take photos and get a statement... it goes on....
all because some guy in eastern Europe wants a knicked white golf for his misses sat in front of his UK housing benefit/child support funded 5 bedroom house.... makes me sick!