British media reports there is a bit of a dispute between Audi and Fiat Chrysler Automobiles (FCA) regarding the "Q2" and "Q4" monikers.
FCA-owned Alfa Romeo used the Q2 and Q4 naming to denote whether a model has either a two- or four-wheel drive layout such as for the GT Q2 and 159 Q4 depicted in the attached images. Nowadays, these monikers are used by Maserati for the same reason on their Ghibli and Quattroporte models and it seems FCA isn't willing to let them go that easily.
Audi is very interested in purchasing the rights to use the names for a couple of (yet more) crossovers but FCA CEO Sergio Marchionne doesn't want to sell. It seems Marchionne has a bone to pick with Volkswagen chairman Ferdinand Piech which is why he doesn't want to sell the rights for the Q2 and Q4.