Worryingly i found this small clip run over in my drive:

Now 99% of the time i park my Audi B5 S4 on the drive, although there is a small change it could be off my wife's golf TDI! I have driven the audi and the golf since finding it and the audi seems a bit down on power, but i'm not sure if its just my imagination... as its not drastically broken.
I have had the top covers off the engine and i can't see it missing from anywhere. Any suggestions? It has a number on it -113 and a code that is hard to read -OE1 PAT maybe.
I know this is all a long shot, but i'm really after some suggestions as under the bonnett there is a forest of pipes!
Thanks for any help you can give!
Matt