I have an older model Advance that does not have the factory crossover tube and is starting to get "gummy". I plan to completely disassemble and un gummy it before the season starts. In order to avoid the gummy thing in the future I'd like to add the updated crossover tube. I've read the older thread here where the fella over engineered the hell out of it. The factory tube looks much less complicated. Has anyone here done it? If possible I'd prefer to avoid having to ask the dealer about it and having him try to tell me it's rocket science or brain surgery and should only be completed by an authorized Harman tech. Thanks for any help anyone is willing to offer