Generally a car is considered a total loss when the cost of repairs exceed 70 percent of the value of the car. A newer model would become a total loss when both airbags deploy and the frame is bent and can not be straightened. I would contact insurance companies for more information.
〉 Answered on Jan 29th, 2010 by Jenny Trostel, Partner at Anderson of Hunt Valley
You might find this article at AskPatty.com to be of use answering your question: http://caradvice.askpatty.com/ask_patty_/2009/09/how-does-your-insurance-company-value-your-totalled-vehicle.html