I think the clicking you hear is the calipers going through a normal process. In other words, you're supposed to hear that but only during the first 500 feet or so of driving the car.
Here is a link to the current recall results for the 2000 celica - http://www-odi.nhtsa.dot.gov/cars/problems/recalls/results.cfm
All they will do about the drl's is place a resistor in there to tone down the brightness. I personally wouldn't worry about that recall just the master cylinder one.
I've posted this other places but I'll say it again. I called Toyota 10/04 and was told there was no recall on my VIN. Last month I get the recall letter in the mail. I make an appt to have it checked out and it qualified. The next week everything was fixed.
FOR ANYONE NOT TAKING THIS RECALL SERIOUSLY, I really think you should. Chances are most of us won't have to have anything replaced, but some of us will. All the people who are not the first owners of your Celica please call this number (1-888-270-9371) and have them update your information. I strongly believe that was the ONLY reason I got the letter in the first place!! Some people say they use the current registration info but it's better to be safe than sorry! And have peace of mind that if any other recalls come out Toyota will have your current info on file to send you out the proper notices.
Good luck everyone