Unless you want to find a car out of state which is very low price, do not save any money because they would have to pay TX sales tax when registering the car.
I had sent my car to TX from FL, as it was a bargain, even after the cost be to have it shipped here. I paid 6.25 % tax on the sale price of the car, the registration fee , the inspection , and got a decent deal on insurance.
One suggestion , since it most definitely needs this car once you pass - keep a small emergency fund medicine for your car, separated from all other expenses, to cover any repairs that are not under any warranty, etc., or covered by insurance. Also take into account the condition of the tires because the roads are murder TX wheel and a new series that can easily spend at least $ 500.