Yuji Yokoya, a Toyota engineer, was given responsibility for re-engineering a new generation of the Toyota Sienna minivan for the North American market. So he drove one more than 53,000 miles across America, from Anchorage to the Mexican border and from Florida to California.

Crossing the Mississippi River by bridge, he [Yokoya] noted that the Sienna's crosswind stability needed improvement. He observed excessive steering drift while traversing gravel roads in Alaska, and the need for a tighter turning radius along the crowded streets in Santa Fe. Driving through Glacier National Park, he decided the handling needed to be crisper. He also made an all-wheel-drive option a priority, along with more interior space and cargo flexibility. Finally, he decided that the new Sienna would have to be a minivan that families, and especially kids, could live in for extended periods of time. Upgrading seat quality became a priority, along with “kid friendly” features such as a roll-down window for second-row passengers, an optional DVD entertainment centre and a conversation mirror so parents could monitor what was going on in the back seat.

http://www.economist.com/node/14299017