You could put the Rushmore retractable tether on. It's a 1/8" nylon cord.
Part #13 and if you do don't forget the (5) screws (item 8)

http://partsfinder.onlinemicrofiche....=79&c=0&d=2016 FLTRU ROAD GLIDE ULTRA (KGL) TOUR-PAK - COVER

 

Ordered mine about a month ago, full price shipping and a handling charge??, which I thought was high at the time also. I order regularly from an eBay seller in Arizona and he ships similar weight packaging to me for $5.99.

That said, I bought it and it is well worth the money, extra charges and time to install. Use the video on their website to help with install. It is as easy as they show. I would add a drop of blue loctite the the fasteners but I put blue loctite on just about everything.
Customer support is excellent. I had an issue with mine and Patrick was helpful with quickly emailing some pictures to help me out.

When you use it you will wonder why you waited so long to do this.
I used mine on a recent trip with a bag on the luggage rack and it supports it easily. I was never comfortable with the tether and thin cord holding a loaded bag on the tour pac lid.

The best $100 you will spend on your bike.

 

I put the new hinges on with the HD retractable tether for now. I think I will however cough up the cash for the eglide hinge; a $100 is far less than a damaged Tour-Pak and just the fact that I now know the cables break now worries me.

 

I am also going to buy this item for my tourpac - However, when we travel and have items on the luggage rack - mostly just rain gear or light items - I NEVER allow the lid to hang open with items on the rack - I really do not believe any hinge is designed to support the weight of the lid AND a loaded rack - IF we need to get in the pac - one person holds the lid and raise it just enough to get in an out. If I were in need to open the lid all the way - I would first unload the Weight off the rack. Regardless if I have this new Eglidegoodie item