i don't know here if anybody has done that with his sprinter. although a saw a guy who had totaly removed the "iron part, which is below the foam of the seat" and made a seat with only foam n leather cover from somewhere. with that alternation the bike started looking like chopper and also one more positive thing that the height reduced. but i did'nt like that because practically when riding, it was putting more stress on shoulders.....that's what i feel. It may get better if someone puts attention to that and improve that thing.....(i had a drive for about 100 m)
second the suspension, i once saw a man on road with three person behind him, he has put the shocks of like Chinees CD 70, with a long spring outside. i asked him about on the go, he replied that now it is much better and he is a machanic so he was able to do that.....
check if u can spend ur time and make a good things....