RX350 2008 engine repair help

[Kaz]

Hi guys,

My RX350 heated up and the engine shutdown while we were on the road. The insurance has refused its repair citing mechanical failure. I am wondering what are my options now? I have been quoted $3000 to $7000 (parts+labor) to fix the engine which includes head gasket, thermostat, time chain, and other parts. The other option is to sell it to a wrecker. 

I am not sure which way to go. Looking for advice on what would be the best option. Right now, I am able to start the car, and a few drops of water coming out of the radiator. 

And, below is the inspection report from insurance's repairer.

Quote

Inspected vehicle underbody for damages - no visible damages caused. Engine light on upon arrival, code P0117 indicating coolant temperature issues putting car into limp mode. Radiator cap has failed/broken apart and remains within radiator with signs of engine oil in cooling system. Suspect driver has driven vehicle until overheated and stopped, suspect engine warning light would have indicated driver before pulling over

Thanks
Kaz