2005 CooperS
Cold air is blowing on the passengers feet when moving, but not when sitting still. The heat is working fine though. Where is this cold air blowing in from?

 

Did you figure this out? Is it coming from the vents? Or do you believe it's outside air that is making its way into the cabin of your R53? If so, check the door seal. You can do a water test and spray a pressure washer on the door, by the bottom and sides to see if you can visually watch water seep in.

 

Been there. The cabin filter is not seated right. Open the filter box (right up under the glove box at the passengers feet) and pull the filter out and put it back in right. You'll know it is seated correctly when the cold air stops blowing in.

 

Could be the seal for the steering shaft too.