HELP! Engine Wire Harness.

I want to know if my Prius is dead.

It's a 2006 with 135K. About 3 weeks ago I had a tire separation that caused significant body damage to the bumper and left front fender. I had the tires replaced, but left the damage, for now, as it's only aesthetic.

The only remaining functional problem is some wires in the wheel well had been severed, either due to carelessness of the tire guys or possibly during the tire separation. So several sensor displays were lit and I recently had some battery issues. So I took it to a dealer to diagnose the electronics. They said the wires had been stretched to the point where several sensors, including a speed sensor, had been damaged and the entire wire harness needed replacement, cost: $5,300 parts/labor.

So the car currently functions, but the dealer insists that the severed wires could drain the battery even when the car is not running. I'm skeptical because the car sat for 1 week while I was traveling and it started fine. It was a couple days later that my display went bonkers and the car wouldn't start. But I think I may have left my lights on, because I was able to jump start the car and drive it to the dealer. The dealer also says the wires to the auxiliary coolant inverter were cut, making the cooling system for the battery sketchy. Hence, my car allegedly has terminal cancer and could go any day now.

I'm considering getting a second opinion. I'm in Orange County, California, anyone know an honest dealer or Prius-electronics-capable repair shop?