Dear Mom with Cars: The more important consideration is the number of cars that you own, and not the insurance expenses related to these cars. Florida law permits you to exempt only $1,000 of equity in a vehicle, although if you do not live in an exempt homestead (house) you may get an additional exemption amoutn. The dollar amount for vehicles are not waived because you sons need to get to college. There are no car exemptions based on necessity. If your car is owned free and clear, and the car is worth more than the applicable exemption, you may lose your cars in a Chapter 7 bankruptcy regardless of how much you rely on them. You need to consult with an attorney to better prepare yourself for filing bankruptcy.
This is a judgment call based on the "totality of the circumstances." The insurance on the 20 year old is a stretch as adults are expected to care for themselves. The insurance on the 17 year old may be a reasonable expense if the son is dependent on you and he needs the car to attend school. If you have an obligation to provide for them pursuant to a child support agreement it is likely to be allowed. It also depends on your schedules I&J, how far under you are and the reasonableness of your other expenses.
You should talk to a local attorney who is familiar with the stance of the trustee and any case law on the matter.
It depends on the reasonableness of the expenses. If you are purchasing lots of excess insurance for each car, then the trustee is more likely to object. But if you have basic bare bones insurance for each car, and then some to keep yourself protected, the trustee might find that to be a reasonable amount of expenses. Further, the insurance for 20-year-old will be harder to pass off as a reasonable expenses. If you're a single mother, then some of the trustees might expect the older son to be the man of the house.
As far as the cars go. You only get the $1,000 exemption on one car if you're single, or two cars if you're married. Some trustees may not bother to take your car (or cars) if they are old clunkers that are not worth much. It depends on how expensive it is for the trustee to seize the car, store it, put it up for auction, and eventually sell it for enough money to pay off some of your creditors.
Talk to an attorney who can put more attention to detail about the age, type and condition of your vehicles.