Guilt makes us do crazy things! There is NO WAY i would EVER let him take all of that hard earned money from you.
i know you feel rotten, but please don't. I've been following your story (i sound like a stalker, really i'm not, i just lurk on Parents as Partners) and there is NO WAY i would give that man a dime! A man doesn't take all his wifes and sons money!!!! Have him take you to court. Let the car get repoed (it's in his name right?). Rent one, buy one used, let the car go!!! Do not let him control you anymore!!!