First thing I would check is fuel pressure. If that's O.K., then you can eliminate the fuel system. Well, almost. You're getting fuel to the rails. What about the injectors? Can you hear them cycling? It's not likely that all of the injectors would fail at once, so if they are not working, it's probably and electrical problem. I suppose they get power from the computer. Someone else can chime in if the injectors aren't working.

I would think you have an electrical problem somewhere since this started after you washed your car.

Although, if you got water in your gas tank, that would definately cause problems.

Hope this helps. Good Luck and keep us posted.