I bought a car with my father consigning for me. I have been separated from my husband for 18 years. I'm getting the divorce currently and I found out my husband can possibly get the car. Since my dad consigned for the car loan, can he get the car in his name only so my name is off and my husband can't get the car.
Ownership and loan co-signing are different things. Just because your father co-signed the loan does not mean he owns any part of the car. You would need to check whose name is on the title. I would expect it to be just you.
In a divorce any and all property is open to division between the partners. However it is unlikely that after eighteen years a car that you presumably bought since then is going to be specifically given to your husband, unless he has been paying for it. Most divorce settlements are by agreement anyway, so it is likely that you could substitute something else for the car.
The only way of absolutely preventing the car (or anything) from being part of the settlement is to sell it or give it away. However doing this and keeping the use of it will likely be seen by any court as an attempt to hide assets and could get you in more trouble.
Presumably you are using a lawyer for the divorce. Talk to the lawyer.