On a recent trip I noticed something strange (at least it appeared that way to me) whenever I'd fill up (top off) the fuel tank. When I pulled away from the pump after having "filled her up" the fuel gauge read "full" and the needle actually pointed past the last white line there (normal for a REALLY full tank). However, as I would drive maybe 10 miles the gauge would drop to just before the "FULL" indicator. Then for the next 60-80 miles it didn't seem to budge. Then, for the next 100 or so miles it would slowly inch toward 2/3rds full (that's when I'd notice it). My question is why does it the gauge drop so rapidly on having travelled just 10 miles (at highway speed) and then proceed in an expected way down to half a tank? (which is where I usually stop to fill it back up again).

Now, the rear wiper on a turbo wagon. In the morning, it comes on by itself, does one sweep (and I know it's turned to the off (middle) position). Any ideas what might cause that (I always shake violently at the thought of having to trace something electrical in this car).