Keyboard coffee spill - repair.

I hope you were joking. The carwash is the last thing you want to take the machine through. Those vents in a G5 would let water in and it would corrode the logicboard if it was allowed to stay wet for any significant period of time. If your G5 is otherwise working, leave it alone.

In the future never have food nor drink near your machine. You are asking not to be hit by Murphy's Law. My college would expel any student who brought food or drink to their computer room.

Just for anyone reading who's thinking of trying this, it is absolutly critical that the keyboard be completely dry, inside and out before you attempt to reconnect it to your computer. If there is still water inside the keyboard, you risk a short which could permanently damage the USB circuitry in your computer. Drinks with sugar or, worse, dairy products are very difficult to wash out (if they've dried, it's almost impossible), so to me it would not be worth the risk to save the relatively minor expense of a new keyboard, but if you do try to wash out your keyboard, please keep this note in mind.