hes overdrawn on all his bank statements he sent you ? I dont think the embassy will take notice of the car as an asset, as the embassy want to see he has the finances to support you so you will not need recourse to public funds, that means money in a bank account.
has he not sent you evidence of any savings in a bank account ?
it would have been better if the photocopy was certified as true, but many people don't and have got their visa , so it shouldn't be a problem..