An easy upgrade when loading your Sienna as loaded rear height is a known weakness of this van. We had our Sienna campsite loaded up in 2015, including 3 bikes on a trailer hitch. This helped keep the ride height closer to normal and greatly improved ride and handling. The road was in terrible condition with many twists and turns and the van behaved very well. Helps minimize roll in turns and smooth out bumps and dimples. This was the first flight with a large load, so time will tell the durability of the product. It is also recommended to use a 3/8" wire harness when installing to cover the catenaries and you will of course need more zip ties (only 6 included).