Mobil 1 V-Twin is good stuff. On the back rest question, are you talking about for yourself or a second rider? If you are going to be riding 2 up a lot, check into a passenger peg relocate kit and a 1000 lb spring. It might help if you let us know what year your bike is as the seats are different for early years. Also, welcome to the 4M, but hide your credit card as there is so much you can do to these bikes you can bo broke quick.
I know the voices aren't real, but they do have some good ideas.