the purpose of most enclosures is to control air movement behind the driver. The purpose of the baffle is to seperate the front from the rear. Air control doesn't happen with IB. It was mentioned that in a car it isn't a true IB not necessarily because of the air (prolly no problem there) but because all soundwaves are joined in a vehicle and true seperation of the front waves and the rear waves are basically impossible. That's my point. With wave cancelling surfaces and, therefore, less sound in the trunk, is there any theoretical gain in performance that can be had? I'm sure not saying I know the answer, only that its a decent question.