My mom also has arthritis and heel spurs and if my stepdad said something like that, I'd nut him.

On the other hand, him taking your car to have it fixed may not be a bad thing. My dad used to take care of my car, but it broke down this past spring and my husband and I had to buy a new car. I have a 2010 Chevy Aveo5, and our car payment is 270 a month, and the insurance is 175. Together, that is nearly the same as our rent. In between my old car (which was a 04 kia rio) breaking down and getting this new one, I had a 96 subaru outback and I will be the first to tell you that having at old car that NEEDS fixed is a pain. I was at the mechanic every week for the three months I had that outback. I ended up paying $4000 for the car, $2000 in work done to it, and I only had it for 3 months. Having work done to a car costs SOOO much, that's why my husband and I decided to go the route of getting a new car so it would be under warrenty.

But yeah, long story short, if he wants to throw his money away on your car, I say let him do it. Less you will have to worry about later.