Ok guys, how do I go about mounting my rear speakers in the package tray? I know this may seem like (or maybe it is) a dumb question, but how do I physically mount them, while still getting a cover to mount on top and not have a high spot in the masonite package tray? Do I need to get a particular set of speakers? I assume they are to be bolted to the steel structure to avoid rattles..... Some guidance please.... Thanks in advance!