About the breach of contract in renting a car: 1. You have signed the lease contract, which means that the contract has come into effect. 2. If the company wants to change cars and you don't agree, it is a breach of contract for the company to act according to the contract; 3. In case of breach of contract, you have to pay liquidated damages. If the amount of liquidated damages is not agreed, you can make compensation according to the losses caused to you.