Thank you. I will fill it immediately. I thought that it was odd to have an empty tank under the hood (but I wasn't sure why it was hidden behind a cover next to the windshield).

If I'm lucky, then this will also explain the 5 drops of dark fluid on my floor each night. When I did the oil filter housing gasket change this weekend the brake light came on at first startup after the procedure. I started it a few more times and the light went away. I thought it was just a result of the battery being off overnight and didn't pay attention to it. Now I know that it was an early warning to my condition.