Is a car dealership a secured creditor?

No, unless that dealership is of the buy and driver variety. Dealerships are that, a dealer in vehicles. Dealerships do not typically provide financing; this is typically the venue of the finance company. In the event the dealership is a buy and drive, then yes, they are a secured creditor. That is, of course, they are lax enough to not actually secure the vehicle they sold in the loan contract.