George Clark of Wisconsin should know. He and some fellow dads were coming home from Boy Scout Leader training when another car pulled right into their path. They hit it going 50 miles per hour and the untethered child booster seat next to Clark slammed into his head, crushing his cheekbone and jaw.
"I basically had facial reconstruction," Clark said of his recovery. "In today's environment, with the airport security, I probably look like the terminator."
"Very Humpty Dumpty," his wife Lynn Clark said. "That's exactly what it must have been like for him to put all of these crushed pieces of bone back together again."
Safety Research and Strategies, an accident investigation company, estimates ordinary objects in cars are responsible for 13,000 injuries a year.
At 55 miles per hour, a 20-pound object hits with 1,000 pounds of force -- so powerful that a suitcase can literally sever the arm of a crash test dummy.
"From head impacts to serious internal injuries, it's a wide range depending on the severity of the crash," Sean Kane of Safety Research and Strategies told "GMA."
One study showed how unbelted passengers are a danger not just to themselves, but to others -- because people can become projectiles themselves.
"Even something as small as a can of peas can become dangerous," Clark said.
As for Clark, he's had multiple surgeries and racked up more than $60,000 in medical bills.
He said he wanted his story to be your cautionary tale.
If you have a summer roadtrip planned, you might want to re-think how you're going to pack the car. Here's some more advice:
Check your owner's manual to find out the weight limit for your vehicle. Even giant SUVs shouldn't be overloaded.
If you're going to strap some belongings to the top of your car, make sure they're no higher than 18-inches and no heavier than 100 pounds. Too much height and weight can contribute to a rollover.
Whether it's groceries day-to-day or suitcases on a roadtrip, first storage choice should be the trunk of the car. That way there is no way for those items to fly up and hit you.
If you're driving a minivan or an SUV, learn to love the anchors and tethers that come with the vehicle or buy some aftermarket ones. You want to secure all the objects in the back of your vehicle this way.
Now let's talk about the booster seat issue. Booster seats are just supposed to raise kids up so an adult seatbelt fits them properly. They are not attached to your car in any way. (I prefer a jumbo-sized car seat for older kids that is attached, but that's another story that we've talked about before.) To keep the booster from going airborne when there's no kid in it, ideally you would remove it and put it in the trunk. If that's not possible, you want to buckle it in with the seatbelt just as you do when a child is using it.
Since even small items can hurt you when they take flight during a crash, you'll want to make frequent enough stops to get rid of your trash. Clutter is not a good idea.