any feedback
Maybe you beat him down so far, he doesn't want any of his buddies to know?
If it is cash money, I doubt there are any tax consequences.
Do you have all parts and condition of them in writting signed by the seller and notorized?
The bill of sale needs to be specific also to give you any hope of recourse should you need it. Like if it turns out the car has stolen parts on it when you purchase it.