Random Hose?
 

Found this in my car and i havent got a clue what it is..

Its just under the right side of the top mount, under the DV.

http://img560.imageshack.us/img560/1619/25052011182.jpg

Is it blanked off inside? your car should have a blanked off hose somewhere that went on the original dump valve.??

no its not blanked.

It looks like a recirc to inlet hose for a recirc dumpvavle. You need to make sure it's blanked off. Or if you're fitting an original dumpvalve you need the recirc vent to attatch to this (check ofcoarse it isn't blocked first)