Hey Tired....I just finished doing a complete tear down, repaint and reassembly of mine so I am very familiar with this problem!!
Coupled with the fact that I work for an Auto Body Repair shop....There is no solution for this problem unfortunately! You can still purchase the RT side of the trim extensions on the spoiler but the LT side is discontinued which is the first problem. The second is the tabs breaking....Honda never intended for these parts to be removed. You may have gotten away with it if you were skilled with a trim panel removal tool set and a steady hand when the white clips attached to the tabs were still supple, but not now. Almost every one I have ever seen is slightly yellowed and will break with a stiff wind blowing!
What I did was purchase a new one for the RT side and then I glued the tab back on as close as possible like it was on the LT side with some 40/50 or epoxy resin. That is really the only option you have man...The Center one can be held on with screws if all the tabs are broken off so that really isn't a biggy. Anyway, hope this helps man.....Have fun!!