Gas bars disappear despite showing ample gas range remaining

I think there are a few bugs in the software.

As far as reading the fuel level is concerned - a vehicle will often perform an average of the readings over a longer period of time if the vehicle is moving (several minutes), or if the vehicle is stopped on level ground for a shorter period (such as 10 or 15 seconds) the computer can be certain this is a more accurate reading and will update the level. I've specifically seen documentation that Chrysler does this, and if you'll notice very shortly after you exit a highway and come to a stop your estimated range remaining (gas) may drop by 5 miles or so as the fuel sensor is able to get a more timely and accurate reading than it was while you were moving (I've seen this behavior in several different brands of cars, including Chrysler, Acura, and the Volt). Although the issue we're seeing in the Volt could absolutely be a software display bug, as the computer should know the level of fuel that the vehicle last had and (especially in the Volt) that the fuel cap was not opened.

Some other bugs I've seen:

When I got the notice that I needed to run engine maintenance mode after 6 weeks of being solely on battery some of the text repeated itself many times in the message box.

And I think the delayed start charging time calculator has a bug in it. I set my Volt to charge from 9PM to 6AM (off-peak) and to attempt to fully charge for departure by 8AM. I generally charge at 120V, so the system defaults to 8 amp charging and calculates the time based on that. If I get home with an empty battery at a time like 5PM the car calculates (rightfully) that it should begin charging immediately so that it's full by 8AM at 8 amps. When I switch to 12 amps, the car still starts charging immediately, even though it could fully charge off-peak solely between the hours of 9PM and 6AM (or start at 9PM and definitely be full by 8AM).

Every once in a while upon a restart the radio will forget where it was on your playlist, and/or the source will reset to FM.

There are some interesting things I'd really like to see in the source code for the Volt, but I'm pretty certain GM is never going to release it to the public.