All Cardboard boxes, paint (tones of it) and other cobra vehicles.

I was planning on making this set where it had a lot of machinery and stuff in it but I decided against it.

My opinion, Maintenance Bays are made to look dingy and somewhat rundown. If you notice the glue that was trying to drip off of the walls, it accidentally ended up looking like the walls were were slowly decaying.

Overall, I think it turned out well...for now. I will be adding more pieces of the set in time.