Personal effects are typically not covered on your personal auto policy. Instead if your personal items are stolen or damaged in while in your vehicle they would usually be covered by your home owner or renter’s insurance policy.

Some companies may offer the ability cover these items on a personal auto policy on an endorsement basis.

Per the 1999 state of Florida (10th edition) general lines agent study manual, it is called the "Audio, Visual and Data Electronic Equipment and Tapes, Records, Discs and Other Media" endorsement. It will cover up to $200 in losses for tapes, records, discs, and media owned by the insured, while contained in a covered auto. Some companies may call this type of endorsement a personal items add-on.

So your own insurance company would not normally cover the items in the trunk that were damaged. You asked about if you were hit from behind. Property damage liability coverage of the at-fault party normally pays for the damages to your vehicle and not items within your car. However if you prove that the person hit you in a manner that your laptop or other personal items were damaged as a result of the accident you may be able to negotiate with the at fault party's insurer for these damages.

State laws, insurance policy terms, and guidelines of insurance companies all vary though so this is an issue that would need to be taken up with the insurance company involved in the claim. To see if any state insurance laws would govern this particular situation you can check with your state's insurance regulator.