That is what I wonder. More so, I wonder: How are they rich?
In a Japanese context, real estate agents don't make much money, I assume this since Misaki actually has free time to spent with her daughter.
The entire reason Misaki is spending so much time with her daughter lately is because of crippling guilt over not being there for her before the accident that severely scarred her face, and while I'm not an expert on expensive car maintenance I don't imagine the upkeep is so extreme that they'd need to change to something cheaper a couple years after easing off on the amount of time she's out for work.
She was basically never at home, aka always working, for 10+ years. She can afford some family time and expensive things because she’s constituted a capital previously.