[TTV8M]

For the rear sound issues it sounds like your rear amp is either wet or blew a fuse. My x6 is notorious for water ingress from the sun roof tubes getting clogged

For the breather hoses , you can chop them up and put in catch cans. I did this and am happy with the results. Still have to clean up the mountings and stuff. You can search for catch cans here in advanced search and see the original post by sophisticated red neck. He has links to the cans from Amazon and the hoses with clamps. You do need to be able to tap plastic and chop up the factory connections. So you'll need a vise to hold things in place, the proper drill bit for the thread taps, etc.