You can take the door on the PS side panel off & then are able to see if the HVAC vent fits loosely in the duct work. The HVAC vent will just pop out of its dash mount; sometimes removing the side panel door helps gaining access to pop the HVAC outlet loose from the dash & slide it out. Be careful removing the HVAC vent; the small locking tabs (2 on top & 1 on bottom) will break off after the plastic has aged over the years. Combine that with foam insulation that's deteriorated, and the HVAC vent is not longer being held securely in the dash & ductwork. The 2 locking tabs on my DS HVAC outlet have broken off, but the foam insulation is still in good shape. So the HVAC outlet seems to stay somewhat secured in its dash mount.