McLaren have gone through a difficult season, but a proper look at their new MP4-31 suggest they have put in considerable effort to come back from that swiftly.
A place to discuss the characteristics of the cars in Formula One, both current as well as historical. Laptimes, driver worshipping and team chatter do not belong here.
Mercedes hasn't had the need to use that changeable outer structure on their gearbox anymore. They only did it in 2013 when they were messing around with the tyres. Once they figured that out they had a more conventional single shell gearbox housing from what I have seen.