I looked into that briefly for my 2004 RT. I wanted the Russell Day Long seat company to build a GTL style backrest for my top case. What I got didn't work and I broke the wooden support board inside the backrest trying to install it. The ultimate solution was expensive but worth it to me. I bought a 2010 Goldwing for my 2 up bike. My wife loves it and can go hundreds of miles now without pain or being one. Previously about 60 miles and she was squirming and complaining.