Complex sentence: Unsurprisingly, the M30 convertible weighed even more, due to massive amounts of body and chassis reinforcements, but this is regarded as a good thing to some, because the chassis is noticeably stiffer than it is on the coupes.
Split into simpler sentences: Unsurprisingly, the M30 convertible weighed even more, due to body and chassis reinforcements. This is regarded as a good thing to some, because the chassis is noticeably stiffer than it is on the coupes.