If you want to get them off your back for good without feeling guilty, go to your bank and tell them you would like to take out a loan for your sister and her husband who don't have jobs, but want you to take out a loan for them to buy a car. Tell them the car will be in their name, so you won't have collateral.

The bank will say no. Tell your sister you talked to your bank, and they said no.

If they push for details on how you requested the loan, tell them the truth. You can tell her you absolutely did not want their car to be in your name, and you didn't qualify if the car wasn't in your name.

Too many legal ramifications having someone else's car in your name.