They don't like being slammed, i found that shortly after slamming my boot to get it shut i had to reset the whole boot lid and latching mechanism to get it to sit right, so i would definitely not resort to force to get it to shut. i think once its shutting properly i very short but positive drop (2-3 inches), with your hand just pressing it into place, is the best. Anything gets in the way do not force it, move whatever is in the way and then close it. I had many issues with the boot lid including the seals leaking until i got my zen going and treated it with some respect and its been good for quite a few years now. The worst of it is the bolts that hold it in place are all sliding mounts, so there are a million ways the boot lid can move on its bolts, once some thing gives it can be tricky to get it back where it should be, be careful.