I recently bought a bunk car at an auto dealership. I drove it the first day, and after that the vehicle wouldn't start. The dealership mechanic said it was a dead battery due to a drain by a crappy factory radio. My first question is, why would the factory installed radio do this now in all its 10 years of life? Before buying the vehicle, I requested it's records. Nothing severe was seen on the records. After I bought the vehicle, it was brought to my attention that the dealer omitted very important records from me. I only received partial info on the car. They omitted the portion that made electrical issues apparent, and I would not have bought the car if I knew those things. In the time the dealership owned the car, three NEW batteries were put in as each before died. The missing records showed this and that little to no investigation into it was done. What should the mechanics have investigated when replacing the NEW battery?