No, typically comprehensive coverage does not cover personal items stolen out of your vehicle. Comprehensive coverage is there to mainly cover the vehicle, not the personal items within it. So if the car was stolen then you could place a comprehensive claim for the value of the vehicle, not usually though for the personal items within it.
Automobile insurance policies normally only pay for auto-related equipment, not personal items stored in a car. If you had personal items, such as clothing, luggage, gifts, laptop, CDs, money, etc. that were stolen from or damaged while in your vehicle, your policy may not pay for them, or may pay only a limited amount. However, if you have a homeowners or renters insurance policy, your personal property may be covered under that policy.
Contact the insurance agent that you have your homeowners or renters insurance policy through to see what you need to do to make a claim with them. You will likely need to be prepared with descriptions and receipts for all the items so that you can be properly reimbursed.
Personal effects are typically not covered on your personal auto policy however some companies may offer the ability cover these items on an endorsement basis. Your homeowners or renters policy may be able to cover your car's personal items that were stolen though. Keep in mind most of these types of policies have a $1000 coverage limit on expensive personal items such as jewelry, furs, cameras, musical instruments and fine art. You can purchase additional coverage for these items if you find this is needed, but this is something to discuss with your insurance agent for your homeowners or renters insurance policy.