While many consumers purchase warranty plans for piece of mind, they may find companies refusing to provide coverage.  Here are some typical defenses. pre-existing condition-  any evaluation of the vehicle should have taken place when the policy was written hidden disclaimers           check the company's literature and see if the promises conflict with disclaimers.  If so, that may be false advertising. lack of maintenance         coverage should accord with the reasonable expectations of the insured and minor gaps should not bar coverage.