I wouldn’t be surprised if, in terms of cubic feet quantity, there is more wood in the plus 6 than in a trad. There are some hefty pieces in the sills, quarter panels and at the rear end for additional crash protection.
1969 4/4 1995 plus 8 1996 Plus 4 4seater 2002 Aero S1 2013 M3W 2014 Plus 8