Not sure about the load capacity thing, but the trunk space shrinks when you order the optional rear A/C unit. In the GS45h it is the hybrid battery pack that takes up the trunk space. Goes to show that Lexus engineers aren't as foward thinking as some would like you to believe. A Mercedes or BMW or Audi wouldn't ask you to make such compromises, especially for a rear A/C unit. Thats ridiculous for the simple fact that if you need the extra rear A/C unit you must be carrying more passengers, yet you have to decrease the amount of luggage you can carry. Retarded.

M