What is the most effective way to prevent car theft?

Installing a GPS tracker is one of the most effective methods for preventing car theft because it enhances the recovery chances of a stolen vehicle. In the event that a car is stolen, a GPS tracker allows law enforcement to quickly locate and retrieve the vehicle, minimizing the loss for the owner. It serves as a deterrent to thieves who are aware that the vehicle can be easily tracked and recovered, making them less likely to target it in the first place.

The other options lack effectiveness in crime prevention. An obsolete key does not necessarily help deter theft, as thieves often bypass traditional locks. Keeping the windows down is a significant risk factor, as it provides easy access to the vehicle's interior for potential thieves. Lastly, never parking in a garage may actually increase the chances of theft, as it exposes the vehicle to a greater risk, especially in less secure or poorly lit areas.