Do you allow your kids to eat and drink in your car?

We don't. I have never understood cup holders on car seats. At the longest we are in the car for 30 minutes on our way to church or school. If we take a long trip to Orlando (2hours) or Miami (5 hours) we stop for snack breaks along the way when/if necessary. Is it wrong of me to deprive my kids of liquid sustenance for an hour or more?