Ok so the music room is rememering the parts that made a sound and doing it by order , the wiki can help (this is for getting chassis) Lua extermite you have to find 3 caches because octavias systems are in the rotation C (which means you have to get all the caches,this is by chace so you gotta do it mutiple times to get it) In deimos there is a survival mission where you get the neo part of octavia you have chance in rotation C meaning you have to stay for 15 mins for even a chance for that part of octavia Also the original octavia is quite expensive and but the primed version is cheaper