Collision coverage is limited to the actual cash value of the vehicle, and requires a deductible, which is the amount you'll need to pay before receiving benefits. Higher deductibles lower your premium but increase the amount you must pay out of your own pocket if a loss occurs. Ask yourself how much you would be willing to pay on short notice in order to save on your premium, or talk to your agent.
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.
Auto insurance premiums depend on the insured party's driving record. A record free of accidents or serious traffic violations typically results in a lower premium. Drivers with histories of accidents or serious traffic violations may pay higher premiums. Likewise, because mature drivers tend to have fewer accidents than less-experienced drivers, insurers typically charge more for drivers below age 25.