a LAYERED APPROACH, TO PREVENTING THEFT, IS BY FAR THE MOST EFFECTIVE
(1) keep the car out of sight and preferably in a locked garage when parked
(2) your garage should have an alarm with an incredibly loud bell or siren, that can,t be disabled by killing the power and good locks and video camera surveillance
(3)the car should have a tracking device like lO-JACK
(4) get good insurance with AGREED VALUE pay off
(5) a hidden fuel cut-off switch and ignition bye-pass sure won,t hurt
(6) a fenced yard with at least one large dog is obviously one option that tends to reduce trespassers
(7) parking the car with another locked car blocking access makes its theft take time, and the longer it takes the less incentive a thief sees
(8) redundant, overlapping,motion sensor lighting helps especially if each lighted area is hooked to a loud chime , that bongs when it comes on.
RELATED INFO
viewtopic.php?f=27&t=297&hilit=garage+security