Auto Insurance Claims: Auto Insurance Claim, auto insurance claim, auto mechanic

Question
I was rear ended while I was legally stopped at a red light.  The driver of the vehicle was a auto mechanic for a reputable car dealership and was road testing a customer's car when he rear ended me.  My question is who's insurance company is liable to pay for the damages?  Would it be the owner of the vehicle or the car dealership's insurance?  Both insurance companies have contacted me and I don't know how I should proceed.

Answer
I would file a claim with the insurance company that insures the dealership that employed the man who hit your car. I would also put the insurer of the vehicle on notice that you intend to file a claim with them in the event of difficulty with the liability carrier of the dealership.