[Slam]

Try this: put the car in 3rd gear, engine off. Push car forward and back, rock it a little in each direction. If you can hear a click from the bellhousing area (back of the engine) under the middle of the car, that's the limp tabs on the clutch disc engaging. Means the rubber center is done - I'm with mytrplseven on this one. Lash issues like you describe are usually rubber-centered clutch related.

I find my fuel gauge moves faster the more I drive...