MMC don't like the G56 exhausts describing them as "too large, too heavy and too wobbly"!
Difficult to make them smaller if you want the benefits of free flow without excessive noise. Shame the brackets don't mount to the chassis tube rather than the body in someway.
Have heard MMC use exactly those words myself, but the 'too wobbly' bit is the reason they don't crack and disintegrate like some of the factory pipes..... What we need are some Titanium versions with carbon shields from G56 maybe... :-)
