Been servicing the C5 and while cleaning around a bit took this photo.
Been meaning to ask for the past five or six years.
Main reason for asking is that the vacuum pipe to it is quite loose and may be responsible for the somewhat questionable performance and dire economy.

(clickable thumbnail)
Went through the MOT the day before yesterday and needed new droplinks - VOSA have been nosing around the MOT stations locally so I think they were obliged to find something that needed attention and the dust covers were a bit shabby.
Wondered what the shiny bits were when I crawled under the car to drain the oil, forgotten all about them.