I leave my climate control on auto most of the time and this winter I've noticed that the vents on either side of the PCM don't seem to blow much (if any in most cases) air compared to what the outer vents by the doors are putting out. Even when the outer vents are blowing hard, barely anything will come out the center ones.

Yes they are open

If I use the manual controls to output from the dash vents and crank the fan all the way up I do get air coming out of the center vents that feels on par with the outer ones.

I didn't have it last winter and don't recall how they acted during the first winter, but it feels like something is not right so I'm thinking that in the warmer months is was blowing equally from all vents. That is just a gut feel though.

So for those of you needing heat this time of year, how are your dash vents behaving? Is this normal or something that needs looking into?

 

On my Cayenne, there is a menu option in the set up to regulate how much airflow goes to the center vents. That may be your problem....?

 

I'm pretty sure that is for the vents on top of the dash (around the speaker/clock), but yes I tried adjusting that to no avail.

 

Sounds normal. Heat rises so in winter most of the air will come out at your feet with some out the side vents to help keep the windows from frosting up. The heat at your feet will naturally rise up and keep you evenly warm.
Cold air sinks, so in summer most of the A/C air will be directed at your body from the main 4 dash vents to keep you cool. The cold air sinks down and keeps your legs and feet cool.
It is operating normally - as designed.