[cooperpellaton]

I think you're most certainly right that the negative visualization is a central part of Stoic philosophy as it's applicable today but I don't think you're example is correct in this scenario. Instead, in this case, I think it's appropriate to not drive the car and/or to remember that no matter how old the car is, it is still far-far better than the worst possible reality such as that where the OP doesn't own a car, or has one in significantly worse shape.

I like to practice this own philosophy in my life to remind myself that no matter how frustrated I am with my possessions or with my work that I could be in a much worse place than I am currently. It also helps, a lot, to be a minimalist because it makes you all that much more appreciative of the few things you have (especially when you own good ones!).