when taking my head of last night the bit fell out of me socket the m12 bitt. It was when i was undoing the back left one and it fell straght down a big hole next to it any ideas where its gone??? and how important is it to find?

thanks

 

Well, any metal part dropping into the engine bay that can not be found back is reason for concern. Can cause all sorts of damage even when it's not in the engine. It might get flung in between the belt and a pulley for instance.
I strongly suggest you find it m8.

 

the hole leads straight down to the sump if it's the one on the passenger side