I'm a bit of a newbie when it comes to this sort of stuff. I'm wiring an amp and a sub in the boot of my car. I need to get the power cable from the boot to the battery and i've got as far as the glovebox but can't find how to get through to the engine bay. I can't find any predrilled holes or grommets. Does anyone know where i can look or any other suggestions. There's not much room to drill a hole so that will be the last of my options if i need to. It's a 1999 Vauxhall Astra. Any help would be appreciated.