I owe 15k on the car and the vehicle is now un-driveable

Ugh here we go. I own a 2017 Subaru wrx sti and on the way to work, I noticed a knocking sound in the engine bay. I had it towed to a Subaru shop when I got to work and they looked at it. They started it up and it made a boom and locked up. It’s 100% a rod knock and the motor is destroyed.

I owe 15k on the car still and don’t have enough to pay it off out of pocket. I pay about 480 a month for it not including insurance. I’m not really sure what to do. They said they could replace the motor for 12k or give me a built motor for 14k. And without even really diagnosing and looking under the car, they can see a list of other issues with the car.

What’s the best route to go with this? They said they would buy it off me and part it out which wouldn’t cover the cost of the loan. Is it possible to turn the car loan to a personal loan and just pay it off like I would if it was still a car loan? Any advice helps as I’m in a bad spot