Getting hold of the right security services or security patrol services is a task of some research and findings. You should not sign a contract for even a month with a service provider whom you dont know much about. There can be profound consequences, as you may lose security, money, infrastructure, property and mental peace. Thats because being guarded by a service which is not able enough is as good as giving off money for nothing.
Security services do not essentially have to come in a patrol car. Guards may also monitor the place in cars or simply walk and do the job.