Hi
I have a 56 plate and have exactly the same problem. It seems to be a design fault, as if you get on your knees and feel around the vent, there is plenty of hot air coming out but because of the design of the outlet, it blows straight up behind the dash.I have been thinking about making a deflector to redirect the air into the footwell but have not got around to it yet. I too complained to my dealer and was met with baffled looks and was assured that "no one else has complained". So its, " hail fellow, well met". Sorry I coukdnt help further
Tomdac
February 2008