Policies typically use vague language when referring to acts of terrorism, but they are generally insured by the comprehensive portion of your policy. For example, if there is an act of terror and you need to make a claim on your car, that can only be made if you have comprehensive coverage. Since some circumstances are out of our control, comprehensive insurance is certainly important to have in your policy.
Once you know the approximate value of your car and the cost to carry collision coverage, then you can make an informed decision about purchasing that coverage. Many people find that it's a good idea to cover newer cars, but as cars get older, their values decrease, and you might consider omitting or dropping this coverage to save money on your auto insurance.