If it is the 7/70 warranty (if the car has one) the dealer can handle the transfer for a fee if you are in the time period allowed.

If it is the extended warranty you may have to contact the person that owns the warranty. I don't know why that person wouldn't have cancelled the extended warranty and gotten a refund when the sold the car.

Check with the service advisor at your Chrysler dealership and they should be able to tell you what warranty is left on the car and what could be transferred to your name.