Progressive Insurance misleading, threatening, denial of claims, falsification of report Dallas, Texas

My 21 year old son was hit by a drunk driver at 6:30 in the evening. The drunk driver, in his late model Jaguar, ran a red light making a left turn hitting a Mustang and my son's Impreza WRX. Of course the drunk wound up with minimal damage and even tried to run while my son and the other driver were being treated by EMT's. The driver was caught and arrested for DWI. The other driver had comprehensive insurance with State Farm, so Progressive handled him with kid gloves and paid his full claim. My son has liability because he can't afford more. State Farm, our insurance, will do nothing because of this. The drunk's insurance, Progressive, gave my son a car for four days. Then they lowballed a settlement based on half the value to replace the car. My son had owned the 2002 WRX for two months. He had put new tires and other parts on the car. We have sent them receipt copies for all improvements made on the car, but in return their "mechanic" said the car was only worth $4500. Comparable cars sell for between $8000 and $9000. The mechanic also lied and said the interior was trashed before the wreck, which is untrue, and said there was significant body damage, which is also untrue. There were two quarter sized marks on the driver's side front door. The adjusters have repeatedly tried to railroad my son into accepting the lowball settlement, even after sending many copies of receipts and after telling them we don't have all the ER and radiologists bills. The last time he talked to them, the supervisor yelled at him and told him "no lawyer will take this case (my son hadn't mentioned a lawyer) because the car was too cheap." I think the fact that a guy driving a late model Jaguar was DRUNK and cited for failure to yield right of way, leaving the scene of an accident and failure to render aid should count for something. My son's not asking for a new WRX, all he wants is enough money to replace what was destroyed-a blue 2002 WRX that he had saved for three years to buy. Progressive has been evasive-they never answer the phones but return calls later at their convenience. They have been abusive-yelling at my son and threatening him. This is the most unprofessional lot of people I have ever had business dealings with. We are now trying to decide whether to pursue legal action. This is why lawyers get rich.