The ScanGauge 2 does have some X-Gauges for the Prius 2. Here are a couple links to get you started.
https://www.scangauge.com/x-gauge-co...ius-2004-2009/
https://priuschat.com/threads/gen-ii...t-temp.117335/
Side note: After the SG2 is "trained" for your car, the mpg readout will be more accurate than the one in the Prius. The mpg readout in the dash is a bit optimistic.