I can’t believe my bottle is over 6 years old! (The sticker on it indicates I ordered it in October 2015.) I was able to get a 20-oz bottle (“25% MORE” it shouted.) As I shake the bottle, it seems I could still have as much as 1/3 of its original content. The cap is tightly closed, and I have not opened it recently. I’m basing my optimism on the fact that, as NuFinish likes to emphasize, it doesn’t contain any carnauba wax, which they say breaks down fairly quickly & explains why NuFinish’s protection lasts much longer. I suppose I’ll just have to shake it thoroughly, then open it & see if the liquid is still “creamy”, i.e. not watery, which would indicate that the various chemicals have now separated, making the product ineffective. Any thoughts?