Third party fire and theft car insurance policies are there to provide you with the legal requirements of cover under the law, and they protect any victims of accidents in which your car is involved. Third party policies can cover you for legal fees for hiring a solicitor to represent you for certain cases involving you that go to court. Ultimately though, third party policies are there to protect the other people on the roads on which you are driving. Yes, they protect you financially, but they are actually there because anyone involved in an accident that is not their fault should get compensation under law.
But what about your investment in your car? Yes, you may be able to control what happens if you are in your car. You could drive with clinical care and attention and avoid all accidents, thus avoiding your car being damaged. But whatever you do, if a thief wants to steal your car, there is very little you can do about it. Yes, you can buy an alarm for the car, and even an immobilizer. But as car security becomes more sophisticated, so do the car thieves. Should your car be stolen or damaged in a way directly related to the theft (i.e. damage to the door during attempted theft), you are able to pursue a claim. This is assuming you have reported the theft to the police.
The fire part of the car insurance policy covers you for fire damage to your car, which in many cases could happen should your car be stolen. On many occasions thieves will use the stolen car for a certain purpose and then burn them out in order to destroy the evidence. Fire can also happen through vandalism. Whatever it is, it is normally out of your control, which means you can be covered for it.
Something you should think about is that you are very likely to have to pay an excess should you claim for theft. This is often around £100 and means that each time you claim you will need to pay the first £100. You have therefore insured yourself for the first £100 for each time you have a loss through theft. Should your car have been in a locked garage though, and all other security issues were taken car of, you may not be charged an excess, as you have invested enough in tyring to stop the theft.
Some people think that paying an excess on a third party fire and theft policy is unfair, but the insurers are trying to make you more responsible for your possessions. You should keep anything valuable out of view or even out of your car should you not be in it. Also, reducing the claims outlay helps to keep the car insurance premiums down.