You're only spending 15 to 20 minutes in the passenger seat, so make sure the rest of the time you're modeling good driver behavior. On the morning drive, with your kids in the car, point out tricky things like stop signs hidden by branches. When you pick them up after soccer practice, help them notice the idiots crossing in the middle of the street in the dark while wearing all black clothing. Just because they're dumb doesn't mean you get to run them over.
And speaking of dumb, point out your own boneheaded moves. When you slip through a yellow light, note that you really should have slowed down and stopped there. When you forget to signal a right turn, help your kids see the bicyclist you cut off giving you the finger. Acknowledging your own mistakes is probably more helpful than being perfect.