odix@yahoo.com
Sprinter fan
Yes, the side straps. The bench weight plus four adults is immense. I created (using static web material -- basically seat belt grade webbing same width) longer straps to reach the rear side-wall mount points. I bought an extra set of the side buckles (what connects to the bench to the wall). So I have four OEM buckles, two on the bench and two on the wall with straps connecting them. I only fully strap everything down when I have a trip planned with four adults. And when I had the bench right behind the driver/passenger I did not strap down, just the OEM floor mounts. It was a one-off use. However I could purchase additional webbing and extend the length. But the sliding door side would have webbing in the way.