Na I D velocity shift, velocity dispersion, and BIC value estimates determined via the three methods (circles, squares, and triangles for method 1, 2, and 3 respectively) described in Sect. 3 as a function of the inclination angle, from face-on to edge-on systems (blue and red, respectively). The peak velocity increases towards lower inclination angles. The width of the outflowing component is reasonably stable for all the methods adopted with a mean value around σ ∼ 130  ±  30 kms⁻¹. The BIC associated with a single doublet component, method 1, is favoured only at large inclination values, while methods 2 and 3 provide a better fit in the other cases.