Bangle's Wikipedia entry is here, and here is a collection of interviews and other Bangle-related items. Background on the 7 Series is here, and more details on the 2002-2008 model years E65-E68 are here.
From a styling standpoint, by far the greatest criticism fell on the treatment of the area around the trunk lid and upper rear fender. Apparently it was decided to raise the top of the trunk slightly from that of previous 7 Series. For some reason, Bangle must have thought that this functional change ought to be expressed functionally in the design by way of emphasis. That is, the raised trunk was made more visually distinct than it probably should have been. Images below should help me explain this.