I wasn't driving... will i have a case?

A coworker of mine had gotten into a accident with his car and now looking for a new car. He wanted to buy my car from me. I allowed for him to take the car on a test drive to work. He didn't show up for work for that day. A week goes by and i've attempted calling several times. He finally shows up for work and he tells me that he had gotten into a car accident and now my car is undrivable. He said he was arrested for DUI and he ran the car into a fence. Now... he refuses to pay for the damages and to get the car out of the garrage. Can i sue him "assuming" he has liability at least on his old car. Or how would i go about this situation?

Yes you can, and you may file a police report for unauthorized use and theft.