Attach live rock to overflow partition Wall

[ReefGeezer]

So I have a foot wide overflow partition in the rear center of my 90. I really haven't figured a way to stack rock to the height I want without it just looking like a vertical wall. I have a lot of rock in the tank otherwise though. I want to cut some flat sides on some small pieces of live rock I have, "glue" them to the plastic on the partition, and get some corals to grow on them. Question is, how do I "glue" the live rock (more like base rock) to the plastic. Here's a FTS so you can see the partition.

.

 

[Scurvy]

I went with an “Alternative Reef” magnetic frag rock to get a similar result on my back glass. the external magnets are sealed and could go into an overflow.

There are a few similar magnetic rocks on the market these days. Not sure if all of them have sealed magnets though.