Buying a used car is always a big risk. Even if when concluding a deal you were convinced that the vehicle was in excellent technical condition and carried out a legal check of the car’s documents and history, there are a number of points concerning the car's safety that require special care. Let's take a look at these points.
When we purchase a home on the secondary market, we have no qualms about the need to replace an old door lock or install an additional one. The same principle applies when buying a used car.
Keeping that in mind, if a security system is already installed on a used car then:
as a rule, the warranty no longer applies, so there is no certainty that it won’t fail at a crucial moment;
when selling a vehicle, they very rarely transfer the entire set of necessary key fobs/tags (they’re either lost, broken, etc.). In this instance, it’s not so much the completeness that is important, but the lack of a guarantee that the missing key fob/tag hasn't remained in the wrong hands;
even if all the complete key fobs/tags were handed over, there's no guarantee that they weren't in the hands of unscrupulous individuals. If this is the case, they could have done anything to the security system, including preparing the car in advance to be stolen. For instance, to register an additional regular key, key fob, or tag for the security system unbeknownst to the owner themselves, and as a rule, it’s impossible to check this in a car dealership;
such equipment often becomes vulnerable to ever-improving methods of theft because what reliably protected a vehicle a few years ago may no longer be effective today;
the quality of the security system’s installation and completeness is unknown. For instance, the installation isn't carried out discreetly or comes without necessary items. A car's theft resistance directly depends on this;
it's often unknown what password has been set for emergency shutdown and setting up the security system, or even where the button to enter it is located. In the event of a failure, it won't be possible to disable or set up the security system in an emergency. Yet, there is no guarantee that this information isn't already known to third parties;
even if the most functionally advanced security system has been installed in the car purchased, there are no guarantees that all of the security and anti-theft functions have been implemented.
This doesn't encompass all of the situations you might run into, but it's enough to encounter just one of them to increase the likelihood of losing your car.
That being said, only by installing or retrofitting a vehicle with a new security system that meets modern demands can you protect your car from theft.
Be sure to request a qualified selection of parts for your security system and consult an expert about the possibility of getting them installed on your car.