Got me a blank canvas.

I would show the customer what is wrong and how unsafe it is and if he refused to have the problems fixed I would turn him away, I know its hard to turn away work but you are fixing things that were not discussed on your own dime and if something go's wrong when he is driving it he is most likely to blame you. The world is full of people who do not take responsibility for what they know they did wrong. Be carful. I do hope after seeing your car he will let you redo his.

Jeff