Wireless security systems are SO inexpensive, in comparison.
(if they had a non-wireless system, all the low-life thieves had to do was cut the phone lines)
We were concerned about this, as when our 5er is gone out of the back yard it's a clear indicator that we're not home.
We did three things:
Installed a wireless security system, complete with remote cameras all over this place.
Bought a third vehicle. Now there are always two in the garage.
We have a self-formed and non official neighborhood watch
and all neighbors that we're friends with know when we go camping and agree to watch our place. (we do the same for them) One neighbor's young sons come over to water our chickens and plants while we're gone. They have our cell phone numbers, in case they see something that doesn't look right.
If we're gone more than a weekend, a neighbor across the street (fellow Mason and same lodge member as DH) has a key to the house and our security codes. He comes in to water/feed the parrot, collects our mail, etc.
I detest thieves with the heat of a thousand supernovas.
I hope these scumbag thieves are caught and a judge throws them beneath a jail for decades.
I'd go all medieval on 'em, just sayin....