funnily enough rod, my mates gl has 2 speakers missing as he didn't get the upgrade (dealer demo model minus electric rear seat fold and the sounds)

http://mercedes.harmankardon.com/bro...Class_1012.pdf

he's missing speaker no 6's but was wondering if it would have been worth the hype (plus his kids are complaining that they can't hear in the 3rd row) but seeing as so many german motors have this as an option on the list worth several thousand pounds, surely you'd then not be able to retro fit them as you'd need to reloom the entire vehicle yes?