Rich for the Insurance premiums, I just put that into the expenses side of the equation. So it's figured in the swr. No bucket or fund needed.
I have about 10% in cash, CD, MM (cash bucket). It represents 5 years of money that are used to add to my pension, income bucket (preferreds, muni's, and other income producing investments) to make up my swr. My 'swr' has a bit of fluff in it, so I don't really spend the entire planned allocation, so this adds to (or is left in) the cash bucket. The cash bucket actually has 6 years worth of funds, so the slush is for the roof leaks, the new boiler, and yes even the new (used) car.