I swapped out the old and slightly stretched out factory springs on my super for a new set manufactured by a shop in Australia. They are almost twice as long as the originals providing more coils. This should spread out the stress and prolong the life of the springs. The trunk lid now stays fully open and has smooth action without an over abundance of lift. I recommend these springs to anyone with a saggy boot lid. Changing the springs can be a challenge without a homemade tool such as the one I used based on the method the shop developed.