[jmciver]

As some others have pointed out, the cold start does not sound all that great - similar to the S55. My guess it has to do with emission controls and keeping some of the muffler exhaust flaps shut on cold start (also like on the S55).

I remedied this situation on my F80 Comp Pack by installing a CG Precision exhaust valve controller and set it to keeping the exhaust valves open at all times, including cold start. Problem solved and instant, pleasant sounding exhaust note - including the "GTS Roar". I am sure there will be similar exhaust mods for the G8x in the not too distant future...