Layer one: be a harder target
A visible steering-wheel lock or a flashing LED signals that the vehicle is protected. Many thieves move on to an easier car.
Layer two: noise
A shock sensor and a siren make the attempt loud and short. A glass-break sensor catches the window entry that usually comes first.
Layer three: a hidden barrier
A starter interrupt and a hidden kill switch keep the engine from starting even if the ignition is defeated.
Layer four: recovery
GPS tracking will not stop a theft, but it can help find the vehicle.
Start with what fits
You do not need every layer. Start with a barrier and noise, then add more as budget and risk allow.
A sensible order to add layers
First a hidden barrier such as a starter interrupt or kill switch. Second noise: a siren and a shock sensor. Third glass-break coverage. Fourth tracking. This order puts the most stopping power first and the recovery help last.
Quick answers
Where should I start?
A starter interrupt or hidden kill switch is the best first layer.
Do I need all four layers?
No. Choose what fits your risk.
