Finally got around to fitting a silicon hosed to offside baby doll air vents. I think it has given some marginal improvement. The hose is attached to the vent using a large jubilee clip. (fitted after the photo's taken)

[Linked Image]
[Linked Image]
[Linked Image]

Also tried the near side, b ut the hose I used was too stiff, and could not be bent without putting too much strain on the vent. May at some point source some more flexible hose