I added a stronger seat strut when I put the back rest on the seat several years ago and it has worked like a charm even with the new heavier seat from Mark Hart. I got it from McMaster Carr. I also got my new trunk lid strut from them also as well as a second strut and mounting hardware from them. My trunk lid now stays up even with the rack on there and a slight load. It is worth doing and I am glad I did it. All the part numbers can be found here in the forum, you will just have to do a little searching. It may be that Lamonster has all the parts also.