Hi guys, I'm looking to buy a salvage 2006 Audi A6 S Line. It's had moderate front end damage, the airbags have gone off. The guy selling it said it starts and drives, upon inspection it doesn't, the battery is showing 10% on the in-car display and when you turn the key it just clicks, the engine doesnt begin to start at all. The dash all lights up, sat nav, etc. He said the battery is flat, but then charged it and now that's not the issue. He said a solenoid has gone so the battery isn't giving power to start the engine. I'm prepared to take a chance with the car,, but the problem is he has it on a trailer and he can't take off the electronic handbrake due to that lack of eletrical current! Any advice please!!?