Don't wind em up to high, otherwise you will not be able to close the bonnet properly, some wombat done this to mine, so you had to either drop the bonnet or bounce on front of bonnet for it to catch, which then dents front of bonnet and/or damages paintwork on bumper where bonnet has hit due to the drop.
Plus it will lift level of bonnet above wing line, resulting in 'crap looking car', the rubber bungs are not there to aid bonnet spring, they are to stop bonnet hitting rest of bodywork and stop bonnet vibratation, the spring is due to the catch under the actual bonnet, you will see this has a spring slightly compressed with a large nut type thing, this gives you the bonnet spring up.
Sounds to me your cable is stretching.
PS make sure your bonnet hook is well lubed and working freely, a lot of people don't bother with this device but if it is stiff it will not catch if the bonnet pops whilst you are driving you lose instant vision, damage bonnet hinges, bonnet and sometimes cracked screen as well as peeing your pants, so while you people out there are under bonnet just check the hook is free, for your own safety.
Wow crap spelling,
