But that's the way it is. And neither does your boss. So you're on your own. Get used to it. Make sure the kids understand that college is a co-op deal and that they are expected to contribute to their education.
Children have a way of developing notions of entitlement that are very expensive.
You, meanwhile, should be trying to squeeze out a few years without car loan payments, increasing the cash flow available for education spending. Buy yourself that BMW Z-3 as your graduation present. Assuming you are securely employed, spend your taxable savings down first. Doing so will reduce your taxable income slightly as interest declines. And it will rebuild quickly when the kids are no longer on the payroll.