The countach may be photoshopped but then there were cars by Fiat and hillman that functioned as estates. Fiat's 500 had the engine tuned on it's side to add space.
Aston martin's Lagonda was done up too. Only one made. Suits it too.
and I've seen a mid nineties xj handsomly converted in France too.
It seems estates can look good when you have a go properly.