Yet a different car title question and such a mess of a situation. Any advice?

When my mother became ill she allowed her Grandchild to drive her car so he could drive to her house and care for her 3 pets. Eventually he offered to pay her car insurance to help her out for he was the only one driving. As her pets became too ill from lack of proper care I collected them and he sent money to me to help pay for the vet bills which I was currently taking on. Yes we saved all records. Everyone was helping any way they could. She made us promise to take care of her pets. Eventually he agreed to pay a total of $1500.00 toward vet bills in exchange for keeping the car. That made Grandma happy to have her pets cared for rather than be put to sleep while she was in the hospital and her apartment had to be let go. He eventually put the car insurance in his own name. Now Grandma, my mother, has been in 3 hospitals, a nursing home and currently in an assessed living facility. She has no belongings, no assets and no savings. Her care is 95% of her income. She is on Medicaid and the state has been paying her Medicare premiums for many years. She has dementia and needs 24/7 supervision. The grandchild wants to handle the car legally but is unsure of how to do so. We understand that the sale of the car is an issue and gifting is a no no. Could he just have her add his name to the title so if she were to pass away he would be considered an owner? He is happy to just keep the car as is and continue to maintain and keep up his car insurance but we are unsure how to deal with the registration which has recently expired. Also we worry that if something happens to her then he is really going to have an issue. It's an old car worth mauby $1500.00 it has been in 4 accidents and has no AC, it's very dirty inside and the window doesn't work. Blue book value is 3k due to low mileage but that is not reasonable considering the condition. He has an appointment to take Grandma with him to the DMV in Florida to resolve this in a few weeks but we can not let the DMV mess up her Medicaid because she will become homeless. To make matters worse no one ever found the title. Most of her things were lost in the mess of it all. If he just orders the title and adds his name to it is that considered a gift if she is still an owner? What a mess.