If you park a car in a public storage garage and the space you rented is enclosed and locked - can the car be repossessed?

It depends on the contract you have with the storage garage. Some storage facilities require that property stored have no liens. Some state in their contracts that if a lienholder produces proper paperwork, they (the storage facilities) will allow them access to the liened property. In AZ, if you store property with a lien on it and refuse access to the lienholder, it is a felony ( ARS Title 13, Section 2204). But to simplify the answer, no, a repo company cannot pick, break or remove a lock to repossess a vehicle without a court order. They can open a gate if it is not locked. The Uniform Commercial Code states that when you sign the finance contract, you are authorizing the lienholder or it's agent (the repo company) to enter your property.