You can call your local BMV and cancel the plates. Just tell them that you sold the vehicle and that you have a BoS.
I’m a little puzzled by the “I’m a gear head” comment and then needing to have it towed to have the brakes looked at. And his obsession with the backup lights also kinda puzzle me...I have a 65’ Mustang Convertible and the backup lights have never worked on it since I’ve own it. I’ve had it 20 years now...
Heh, the backup lights on this car was the least of my problems when I got it. I bought it from a place in California with a contract. And on that contract it listed power steering and a power top. Whoops, it has manual steering and a manual top. Plus it overheated after driving about five miles.
I eventually settled with them after they refunded some money for the missing options and send some replacement parts for the engine. (New radiator, water pump...etc) We kept the courts out of it, but they knew they had screwed up.