I have an 2001 z06 and recently noticed a small amount of red oil on garage floor just under rear end. any answers greatly appreciated!

 

Yes I had that problem a few weeks ago. It is the seals around the differential. There are 2 of them on the sides where the axles are. You will see very slow leakage and in most cases it will drip down the exhaust pipe. A few drops a day on the garage floor is all it takes but eventually you will have to get it fixed because you will be starving the rearend of oil.
I just bought my car in August and this happened about a month later. I tried to buy the extended warranty on my car (because it only had 15,000 miles on it) and they denied me. Then I wound up paying a pleasant $750 to fix this leak. The parts are only a few dollars but it is a 7 hour job. Sorry bud.