I have one of the first Contiques (built 9/1994) and the early ones (95 and maybe 96?) didn't have a "low fuel" warning light - I think enough managers in Dearborn running out of gas in theri company cars brought about that change

When I had the original gas tank, the fuel guage was very linear and reliable. After I had the gas tank replaced (recall, I only got one but some people had theirs replaced 2x...) my gas guage started behavin gas you described. The most annoying feature is when I'm cruising at constant speed on level ground, and only have a couple gallons left, it swings back and forth above and below the E line, below the red zone. (I have a red zone on my guage, I think that's another thing that disappeared at one point - saved $0.0037 a vehicle!)
It's been annoying, but I've gotten into the habit of filling up whenever it gets below 1/4 on the dial. If I let it get to dancing around the "E" I still usually have 2+ gallons left.
-Peter