I have Georg Aubele's Flight Information Display gauge installed in all my RTWR aircraft (and most of the other planes).
You certainly have it listed in the hideout as well.
It has plenty of useful information for the RTWR, including, among other,
fuel (remaining, used, time to empty, range to empty),
speed (IAS, GS, and stall speeds as a reminder),
wind gauge,
a page which allows to set com/nav frequencies
and a very useful TOC/BOD prediction.
http://www.flightsim.com/vbfs/fslib.php?do=search&fname=gafid3.zip
I've also attached a modified version where I've added some stuff, mainly Vne/Mmo limitations as a reminder against overspeed. (Modifications thankfully allowed by Georg.)
BR