What's this 411 S5 part?
 

See attached pic. I know what this is, but it's pretty obscure and not a part that most owners would ever see or even be aware of. So I thought it would be fun to see if anyone knows what it is. Sorry, no prizes other than cognoscenti kudos :-)

What's this 411 S5 part?
 

I don't recognise it, but suspect that it's a flexible flap on an air passage, and that the pink things are backing where the material is tied through to something. Is it a soft lining for an air damper on the heating system?
If I'm wrong, this contest is rigged.

guymd, you're getting warm but it's not part of the heater system.

I've attached a picture of the other side - the pink things are rusty rivets that fix two metal plates (one slightly larger than the other) which sandwich some sort of rubberised fabric material which is now perished.

I am a bit annoyed about this because I feel sure I have seen these on a partially dismantled Bristol before. It's a guess, but are they flaps which allow air to pass through the fan cowling when the fans are not running but close up and seal the cowling to force more air through the radiator when the fans are running ?

No, sorry, that's not it. Does such a thing even exist?

I believe the part is common to all 411 series, but I think (not 100% sure) that it is unique to the 411.

Yes, such things do exist on some cars, and Bristol being brilliant aerodynamic experts (!) might well have added such a brilliant feature !!!

Well in that case are they for a similar purpose but acting as sort of non-return valves in the cabin ventilation outlets which eject air through the body-side vents towards the rear of the 411 bodywork on each side ???

Will the answer be under our Christmas tree Christmas Day ?

Thor is correct. There is one on each side on a 411 behind those little vents in the rear wings. However they must allow air in rather than out.


PS/Edit: Actually I think it is the other way around. I think they allow air out rather than in.