when i go to start my s2 rs turbo i do the immoberliser and i here the buzzing then i turn the key but there is a long poors before the car starts but sometimes it doesnt start but not all the time can any1 help me its driving me mad lol thanks

 

Could be solenoid on the starter motor starting to stick or bad or corroded connection somewhere.When it dont start try tapping the starter see if it make a differance.