Bought a 2007 Ford Explorer in 2006 and my wife ran into this problem head on (so to speak). We eventually bought a full back support from a medical supply store that has worked, but obviously interferes with the use of heated seats. Investigating the new 2012 Mazda5, and the redesign makes this problem even worse - test drive was unacceptable. We are looking forward to testing a variety of cars for this feature at the next Auto show in town, in particular the 2011 Explorer redesign with the adjustable restraint mentioned earlier.