The first thing your auto insurance company will do is review your policy to confirm that it even covers theft. Not all policies do. If yours does not, you are out of luck. Often, only plans with comprehensive coverage will pay theft claims. However, if your policy does cover these claims, your company will move on to the next step.
If your policy does cover theft, your insurance company will contact either you or the police to obtain a copy of the police report. Always report theft to the police because they will not pay your claim without it.
Next, the insurance company will likely want to conduct their own independent investigation. They will want a statement from you, and they will will attempt to interview any possible witnesses or anyone else who may know something about the theft. They are trying to find information that may exempt them from having to pay the claim under the policy, such as negligence on your part.
If they do not find any information that exempts them from payment they will now pay you. After accepting payment you surrender all rights to the vehicle if it is recovered. If the car is found, the insurance company will sell it to recoup their losses from paying your claim.
What about stereos and CD players? These items are common targets for thieves, but if you have one stolen the insurance company might not be able to help you for a number of reasons. First, most police departments will not send an officer out to your car to make a written report unless you have a good idea of who stole it. Second, the fine print of most insurance companies excludes claims for personal items inside a car that are stolen. Finally, even if your policy does cover CD players there is a good chance that the deductible will be higher than what they will pay you since insurance companies will claim that the CD player has greatly depreciated in value since you purchased it.