This may sound like a stupid question, but...

I have only been mudding with my truck once, and it was clay mud.  I had to
pressure wash the bottom of the truck, take the rims off to blast off the
mud inside, and when I was done, had to shovel the several wheelbarrow loads
off of my driveway.

Weekend after this I am going mudding again.  Where / how do people who do
this regularly clean their trucks?