I've just fixed a very annoying issue I've experienced since owning my Lupo GTi - the bonnet catch is so stiff that you have to really push down hard / slam down on the bonnet to close it and you have to pull quite hard on the release lever inside the cabin. I've tried cleaning up the entire mechanism with oils, etc. but I've found that it is all to do with the extension spring that is inside the bonnet catch. After a few attempts, replacing this spring to a lighter-tension one does the trick! It will now lock by just dropping the bonnet down and it opens up a lot easier having less tension on the release lever mechanism. Don't just buy any extension spring however - it still has to have enough tension to hold the lever in the locked position. Using too light a spring will not make the bonnet lock at all. The springs I found were stainless steel items that fit perfectly from eBay: search for item number 381125685570 from seller lovelife3l. Nerd Corner: I believe when VW came up with the GTi they overlooked the fact that when they were swapping over the heavy steel bonnet of the non-GTi with the aluminium one, they forgot that the weight generated from the steel bonnet would be less compared to the aluminium design which meant more force would be needed to lock the bonnet!