It's definitely right going through the trim, how else would it go? As far as safety, I'm not sure if anybody else can snag a picture of a donor car's mounting, but I might be able to when I get back to the junkyard. As far as you are concerned with safety think about the mounting differences between the auto belts and manual. There is only one bolt for the anchor. Those four bolts you were talking about are for the retractor assembly, and therefore they are also the anchor for the lap belt. I'm only missing one or maybe two more bolts and all they do is hold the retractor assembly more securely. I really doubt that since that is not an anchor and the b-pillar metal that the retractor bolts into is paper thin, you probably aren't hurting safety too much. As far as that plate you aren't really changing the number of anchors at all, because unless that plate is significantly thicker than those mounting points it's essentially doing the exact same thing. I would like some other member to chime in on this though, and if the consensus is that my method is unsafe, I will procure some plates.