Seriously. I would put a baby seat in the passenger side...say a prayer like every father would...and go. But then again I take a rather agressive appraoch to life. The wife...tell her she gets the day off! Pack a stroller and get the kid interested in cars as early as possible.
I spent most of my car traveling life as a kid sprawled out under the rear windshield of a delta 88 Olds...Seat belts are great insurance policies. You only miss them when you are caught not wearing them...