Sucks that this happened, but could have been worse!
Ever since I bought a new 1999 Volvo V70R I've carried load straps in my car kit, and I tie *everything* down to the handy anchors.
That wagon had these nifty pull-up nets that unrolled out of the top of the back seats, whether they were up or folded down, topped with a sturdy solid steel rod that slotted into keyhole anchor points on both sides of the roof. Had the vibe of a lightweight black volleyball net.
I asked my sales guy what's the deal with that, is it for dogs? And he told me that Volvo had done crash testing for various objects people carry loose in their cars. They found that if you hit a wall at 35mph, the box of tissues on the back ledge of a sedan would fly forward with enough force to fracture the driver's skull.
That image stuck with me.
So everything in my open cargo area gets secured, whether the seats are up or down (usually at least one is down.) Just completed a 680 mi. drive in the Gravity and our soft-sided cooler, luggage, etc all had a 1" load strap through the handles & cinched to the anchors. Takes 90 seconds. Saves skulls & screens.
example straps:
Grab your Shappell Jet Sled Adjustable Cargo Strap for sale at Sportsman's Outdoor Superstore.
www.sportsmansoutdoorsuperstore.com