Seconded. A Model T is ideal because it’s going to be one of the less expensive cars, and will be fairly affordable with respect to maintenance and repair costs.
If they aren’t that well off, then I can picture them having purchased the car before the depression hit, and they would have been very reluctant to sell it during the depression because they would have known that they could not afford a new one to replace it.
They would have also been doing anything they could to save on maintenance costs for it, like having someone in the family do the basic maintenance like oil changes. And they would have kept patching the tires instead of buying new ones if they got a flat.
The automobile repair industry actually grew pretty well during the depression, mostly because everyone was hanging on to their cars as long as possible. If the family didn’t have anyone mechanical who could take care of maintenance and had to take the car to a shop, you might like to have the shop owner / mechanic comment about how his business is doing well even though so many other businesses are struggling.
Car manufacturers were struggling, and were constantly coming out with new whiz-bang features to try to tempt buyers into getting rid of that old car and buying a new one. Many fairly luxurious cars were produced that were sold with very thin profit margins. These newer cars would have made the Model T seem old and clunky by comparison.
The Model T is actually a pretty rugged little car. It’s not exactly a speed demon, but it can handle rough roads surprisingly well. After all, it was designed long before the U.S. had good roads everywhere.
It may not make much of a difference for your story, but the controls on a Model T aren’t the same as those of a modern car. Cadillac created the standard layout that we use today, and Ford didn’t adopt it until the Model A.
Another issue is that the Model T was originally a crank starter, but later models had an electric start. If the electric motor burned out or the starting system had some kind of issue, you could still crank start it, but you have to be very careful cranking a Model T. If the engine backfired while you were trying to start it, and you were holding the crank with your right hand, it could very easily break your hand or wrist.
I’m sure there were some families that suffered with the crank start instead of paying a shop to fix the electric start during the depression, just to save money.
I did a little poking around on youtube and you may find these interesting:
How to Start a “Model T” Ford
Instruction on how to drive a model T Ford detailed