Found a portable chair which when collapsed perfectly fits the lower trunk of a Gen II Prius. It is the Aluminum Teddy Chair by TravelChair. TravelChair Aluminum Teddy Chair at REI.com or Teddy Aluminum 579V| Travel Chair Company In it's carry bag it exactly uses all the width of the lower trunk, and when positioned properly allows the trunk floor to sit flat. This will make vacation/beach packing much easier. FWIW - I believe the GCI Outdoor Xpress Lounger Chair GCI Outdoor Xpress Lounger Chair at REI.com will also nicely fit the lower trunk.
