You're wrong.
The ML, with the glass house, is for the rainy days when His Sanctuary is bored but has to go outside. It allows him to discreetly listen to some music or watch a movie, because nobody hear it thanks to the glass.
The G is used when the sun is shining, so that B XVI feels the wind and the sun, and can have some off-road fun without making the shining white paint and clothes covered with mud.
I think this topic begins to go off-topic...
Anyway the ML is pretty cool too.