STOP! Don't add anything other than the correct coolant to your cooling system! That means no stop-leaks, no additives and no water- ESPECIALLY if it still contains the awful orange/red Dex-Cool coolant!!! Exposure to air (as in a leak) or any incompatible fluids/chemicals turn this (otherwise fine) coolant into a brown viscuous gel that clogs your cooling system. It (dexcool) has also been reported to soften plastics (as in the radiator taks and plastic pipes) and cause major problems, like leaking coolant into the automatic transmission cooler (bottom plastic radiator tank)! I decided to play it "safe" and flush out the system and replace it with the regular "green stuff" (Prestone). You might not want to do that if you're still under warranty, in which case I'd advise you to flush it anyway, and replace it with Dex-Cool (after repairing any leaks, of course). In my case, I may have been too late with my 05 'renza, a week after the change to green my wife rolled in the carport with steam escaping from under the hood. The top plastic tank developed a crack! It has been my (sad) experience that these plastic tanks can NOT be repaired effectively with any type of epoxy or adhesive, so a replacement radiator is in the mail... :_( I hope I don't have to play the "Chase The Leak" game afterwards!
Good luck to you all!
Here's a link about the perils of Dex-Cool and another with damage pics: