 Don't by a AWD Sienna until Toyota figures out how to fix the problem with tire wear.  I had to replace all four Run Flat Tires at 15,000 miles.   My one year old vehicle wouldn't even pass inspection.  The tire tread wear was uneven.  The dealer said it was initially alignment issues, which was not the case.  Bridgestone pro-rated the tires and helped me with the replacement cost, while Toyota did nothing.  Bridgestone indicated that this is a manufacturing problem based on how the tires are wearing down.   Additionally, they indicated that this is a big problem on the Sienna only.  They have helped customers with pro rating tires, but Toyota is not helping.  It's a family vehicle and to have a problem like this boils down to $$ and safety.  The fact that Toyota has done nothing to fix this problem is a red flag for me.  Each tire is about $260 to replace and to only get 15,000 miles out of the first set is a problem.  At this rate, I will put 4 sets of tires on the van by the time my lease is up after only 3 years.