My S550 (A10) has managed 25mpg (US) over 27k miles on 93 equivalent (98 here)
Best was 30mpg (US) on a motorway run over just under 400 miles at 80mph (cruise control on)
S650 will be fundamentally very similar
The main issue with the stock sub is the bass is flabby and boomy. The speaker is a VERY cheap paper cone and it just pushes out a lot of 60Hz poorly controlled noise. The Pioneer is much tighter and more musical without being much louder.
What the same 'help' and 'hints' you have posted 63 times and counting? I'm sure they have got the message (not that they are actually listening)
Oh and I don't want any of the things you suggest, and I AM buying a Mustang S650, so maybe Ford know better than you what their customers want!
OK so let's be very clear - anthropogenic effects have only really kicked in over the last 50 years or so but there were people postulating that human fossil fuel usage would have this effect as long ago as the early 1900's
History of the greenhouse effect and global warming (lenntech.com)...