Keep building them! Its a solid idea and over all great use of space, color and visual interist. One comment the mechanic, as pointed out above has the coldest job of everyone. Aquward positions for periods of time in confined work spaces is never ideal.
In extremes he would 'hoard in' the work area with a tarp keeping the wind out and heat from excapeing. Bare hands on frosty tools is rough even a few degrees below freezing. Improvised heaters were a must for tools in below zero temperatures during a lenghty major repair. A enclosed building was perfect, everwhere else was a compromise.
Parachutes are big enought to enclose a entire vehicle out of the elements. In northern Canada surplus chutes are sold to construction companies for this purpose. * I have no evidence of this practice during conflict.