Golf GT & A4 Avant
Indeed they do, no wax is perfect. 3 coats of BOS is good for 6 months in my experience, I do it pre an post winter for obvious reasons.
Clearly also using incorrect chemicals and strengths also impacts on the longevity of a wax.
durability when only talking time is part of the storey. how many miles will you cover in 6months? And where is the car kept, outside, garage
Even colli 476s will struggle to achieve 6 months in some scenarios