New radiator

My Honda has been losing coolant for a couple of weeks now, so I made it an appointment at Tune Tech for today. (Steph suggested the other day that I drive Phoebe until I could take the Honda in, but that wasn't practical because she too is having a coolant leak. This is the first time I can remember that the cars have had the same symptom at the same time.) The Honda needed a new radiator, which it now has, and I discovered a notation in the gas book that the old radiator had a lifetime warranty. Now I have to figure out what to do with the old radiator (which is now in my trunk) to get the company to pay for the new one.