I love the small car vs. dump trucks/tractor-trailers pics with the requisite "see, they're too dangerous" remarks. Take a look at the front wheel/axle of that tractor, and tell me you'd walk away from a head-on with that rig, at a speed that provides enough inertia to shove the axle back (whether it "submarines" or not), even in an F150. A head-on crash with a semi is a head-on with a semi, regardless if you're driving a Smart car or a Tahoe. You're going to get the sh*t end of the stick.