The headline is not misleading. The point is that if you determine how much car you can afford by the monthly payment the dealer offers you, you get fleeced over the long term. Example, if you make $30k/year, while you may be able to make the payments on a $30k car, doing so will cost you your retirement.
Dave offers the following guidance on how much car you can afford. It is this:
1) The total value of all the vehicles you own (cars, boats, motorcycles, etc...), should not exceed 1/2 your annual income.
2) You need to be able to pay cash
3) You need to have a fully funded emergency fund of 3-6 month of living expenses on top of the cash you are using for the vehicle.
If you don't have a fully funded emergency fund, then you are in the beater market. This means that you buy cars for cash from people (not dealers) who are selling their cars. You do your due diligence on the cars you buy and trade up every year or so. Since you are buying from people, not dealers, you don't lose much money every time you trade.
If you can never save enough cash to buy a car that isn't in the beater category, then there are probably other areas of your life where you are living outside your means.