Once you get that Clymer's manual, take the Banshee apart and grease a few key areas!
This isn't really a mod, but it should be done as early as possible to a new Banshee. You'll be thanking yourself in couple of years.
There are a few design/assembly flaws in the Banshee that allow components to rust together. If these parts are coated in Grease or antiseize, the rust will be minimized or stopped completely. The key areas are:
The long upper A-arm bolt: Just remove the bolt, cover it with grease and re-install it. If you don't do this, the bolt will be rusted to the sleave with in a couple of years and you will only have two options to get it out: BFH (big friggin hammer) or Sawzall.
The swingarm pivot bolt: Same thing, remove it and cover it with grease. Then reinstall.
Rear axle carrier: Disasseble the rear axle carrier and coat everything with grease, including the splines in the axle. You can even put a grease zerk in the carrier to keep is filled with grease. Otherwise you'll need a press or BFH to get the axle out after only a couple of years.