[m6-lt1]

Those screws are definitely the screws for the taillight housing as someone already mentioned. I just installed new taillights this past weekend so I know exactly what they look like. Here’s what happened: there are 3 bolts on each side. You can easily reach two of the bolts by pulling back the truck liner a bit. To get to the furthest bolt on the taillights, you have to pull back more of the trunk liner and to do that you have to remove more of those annoying plastic clips. The prior owner of your car was simply too lazy to do that (and this indicates he most likely had aftermarket tail lights on the car that he removed prior to selling the car).

[Rayvan]

Nice car! Some have said that those nuts are for the tail lights, but I fail to see how they'd end up under the trunk lid's insulation...

[arpad_m]

Originally Posted by Rayvan

Nice car! Some have said that those nuts are for the tail lights, but I fail to see how they'd end up under the trunk lid's insulation...

Yeah, that's a good point, these nuts are probably the same as those used for stanchion spoiler attachment, they definitely look very similar. Someone was lazy either way, that's for sure.

[4xlr8n]

I think the spoiler is the source - this car is a factory RS car which comes with a rear spoiler. However, this car also had (ordered from factory and on the invoice) a dealer installed blade spoiler. I am guessing when they removed the factory RS spoiler, these nuts fell into the trunk lid inner structure...

[GearheadSS]

Spoiler nuts. The installer probably had butter fingers that day and dropped them into the hole on the trunk lid.