I agree with MichaelE. I don't know the circumstances of your step-son having and selling the BMW. It was nice that your husband gifted him the cars. I hope he was appreciative. It sounds like your husband noticed his son needed the cars and gave them willingly, rather than he was asked to provide the cars. From your description, the son is working hard and providing well for himself. Good for him. Gifts shouldn't have strings attached and shouldn't be given if they are going to cause hard feelings down the road. I would not want to see conflict between you, your husband and his son. Personally, I would just let it go.
Natty Boh 6-27-12
Annie 1998 - 8-2-12 RIP