Surface density and velocity residuals of our model as a function of galactocentric radius for the stellar and gaseous components across the Sun’s line of sight with origin at the Galactic centre. Panels show (top to bottom) the stellar surface density, gas surface density, and tangential and radial gas velocity residuals. Running medians and interquartile ranges are shown for each of the distributions, with vertical shaded regions indicating the positions of the bar (grey) and spiral arms (red), and the solar position marked by a dashed vertical orange line.