Most reliable Mazda's?

I actually like my MIL, but she's in her 80s and her son is pushing her to buy a Volkswagen. This is a problem, as she wants a car that will need very few repairs, that she can just get in and drive. Doesn't have to be fast, fancy, loaded, nothing, she just wants one she can trust. I know that Mazda has become the long-term-reliability brand, but not all models are created equal. She doesn't want something new. Over the last couple decades, what is the most dependable reliable rarely-breaks-and-easy-to-fix vehicle out there? Our cars are all old; \`94, 96, and '02, and they are extremely reliable, but we aren't selling any of the three! And frankly they are unkillable rustbuckets. I'm hoping to get her something that's somewhat less rust-bucket-y so that the frame and such are still solid.

What Mazda would you recommend? Figure no more than $15k and she'd honestly be happy with a $5,000 vehicle or even less as long as she couldn't see the road through the floorboards and it was rock-solid reliable ;) We've been eyeballing everything and keep getting conflicting results on what the best models and years would be. Any advice from people that know Mazdas would be appreciated!!!