Don't know about the golf but a lot of bonnets suffer the same at this time of year,I take it you are pulling the cable with grips from the inside of the car!if so get someone else to pull it to open position and you push down and pull up on the front of the bonnet (vigorously) and hopefully you will feel it pop up,the release catch gets gunged up and the spring in the catch hasn't the power to release it,if it does open spray the whole lot with WD40.Works for me.(unless it's something else)nowt to loose eh!
Rich, February 2010
