What's that "Speed Volume" setting do?
 

The manual seems to assume that I already know what Speed Volume is - but I don't. I've found that the setting can be adjusted and I'm ready to adjust - but what is it that gets changed? What's the best setting? (2015 MCS, basic radio).

It turns up the stereo volume the faster you go. You can adjust how much/little it turns it up.

Yup...
Radio gets louder the faster you to...so you can tailor the adjustment to things like tire or typical road noise.

" It turns up the stereo volume the faster you go. You can adjust how much/little it turns it up. " Yep and I think with the newer active sound it works with the exhaust and de-canceller noise.

I have a 2014 MCS and cannot find any sign of this. Is it in the settings somewhere.

Start at Radio (or at Multimedia) > Tone > Volume Settings > Speed Volume. Then adjust the slider right or left. (That's with the basic radio on the '15 MCS).

I've been playing with this adjustment and frankly am not sure it's even working. A little more experimentation is needed.

Thanks for that, i've found it and made an adjustment, next time I go out I will see how it sounds