For a coherent analysis, you should use the median income of two earner households. Two people where one makes $75K and the other makes $50K equals a household of $125K.
And it seems obviously extravagant to me for a middle class family to have two new cars. One maybe, but two? But even so, by the formula, the family can afford two $30K cars.
in 2005, the last actual data I could find that lists 2 income households, the median income was $75,293, assuming that income kept pace with inflation that would be $98,562 today not 125K,
Such a family would not want to spend more than 49K total on their cars. so that is 1 car for 49K or 2 for 24K
and that IMO should be the extreme absolute limit
A 2020 yaris starts at 15,650. With fees, should be around that mark.
The problem is, the median US household does not buy a Yaris. They spend more like double that. So 30-40k PER car, two cars per household.