Dear Idiot Brother-in-law,
You are an ungrateful snot. Pay your god damned car note before you completely fuck up your brother's credit. If my husband and I can't buy a house or get a student loan because of YOU and your ridiculous need to drive a sports car, I will BEAT THE LIVING SHIT OUT OF YOU.
Don't ask us for Christmas or birthday presents anymore. Don't ask for "help" buying a motorcycle. Pay us back the money you already owe us (which is accruing interest, by the way), and start acting like a responsible adult instead of a hissy-fit-throwing child. How can you be so behind on your bills when YOU HAVE A FREE APARTMENT?!
You're a jackass and I can't stand you. Stop coming to the house when Bizarro Dad is not here.