Get some Fenders on your bike.
Not just for Enduro racing. Lots of designs that are lightweight, attach to different parts of your bike and do not take away the aesthetics of your bike. Plus, they come in a huge range of colours and designs that will match your bike or projected image.
MTB fenders like the Mucky Nutz Face Fender or Marsh Guard really stop the mud build-up on the back of the fork and headset, it also prevents rocks getting stuck in the fork/seal area and potentially scratching your expensive stanchions.
Commuter type fenders like the Ass Saver Original stops the water spray on your butt, and are easily folder under the seat ready for the next downpour. The Wit Industries fender attaches lower on the seat tube and really stops the spray gettting into your shorts and into your seatpost / frame area, these attach with a velcro elastic strap so its quick and easy to install and remove whenever you need them.
Keeping water, grit and mud off your bike also increases longevity of your bike and parts and it also means less bike cleaning afterwards.