I was driving down the highway at 65mph when the EPC light came on. Then the lights came on and off inside the car like I had restarted it and then the car stalled and I pulled out off the highway and got towed back to the dealer but it won't start now unless it's jumped. I just bought the car yesterday and it passed all inspections and now my mechanic thinks it's a dead battery but I think it's more. The instrument panel lights also do not come on. It's a 2006 Audi a6 s line 3.2. Please help!!