Hiya just walked by my 56 plate vrs estate this morning and discovered a fluid leak, small. The fluid was coming from the engine area and had stopped flowing but the residue was still there. As I looked under the car this rubber bung (pics) and half a retaining clip (plastic) was on the floor. The position was towards the back of the engine. Anybody got any idea where the bung comes from, what fluid is leaking?

That's a bung for the bonnet cable.

Oh not critical then! :-) Here's the fluid pics for any Sherlock Holmes out there

Try checking all your fluid levels its deffinatly not oil , the problem with a vrs is the undertray will catch the fluid and it will leak from there and not give a true direction where its coming from , try taking the plastic engine cover off the top and have a good look around ,if your car is petrol i would not drive it until you can confirm its not a petrol leak as it will catch fire if it gets on a hot exhaust ,you should be able to smell a fuel leak,