If your car has been damaged in an accident or through vandalism and the damage is likely to exceed the value of your insurance deductible you should start by calling your insurance company. They will recommend the procedures and processes they would like you to follow to ensure your car is repaired satisfactorily.
While insurance companies can and often will suggest repair facilities to take your vehicle, you are not obliged to use those facilities. You can bring your vehicle to any qualified repair facility for an estimate. You are not required to take the lowest priced quote, but the repair facility you choose does need to be approved to proceed by your insurance company before proceeding.