Washing your car in winter - any point?

[bennyboydurham]

I took the barge along to the local friendly chaps of indeterminate immigration status for its monthly wash and vac the day before yesterday and it came back sparkling. After 48 hours I might as well have saved the cash.....



Is there any point? I know that the salt isn't good for the paintwork but I can't help thinking I'm wasting the money.
How often do you wash your P&J at this time of year?