Looking for a used Gen 2 but I am finding lots of low mpgs

That's the thing. Ever go looking for something, find it's not available, no one's got it, no one wants to hear? What you're looking for could be very valid, but you've got to heed the reality of the situation, it'll be hard to do otherwise.

Reset the trip meter with the car warmed up, take the test drive, see how that goes. Also, listen for odd sounds, pay attention during acceleration and braking, cornering. Take a few hills, up and down, watching the charging status. Look the car over inside and out, pop the hood and check fluids, look for anything odd. Lift up the hatch floor and check the spare, tools, cleanliness, any standing water, the 12 volt battery apperance. Look in the wheel wells for rust, under the front and rear bumpers for scrapes, stuff hanging, and the rocker panels for scrapes/crushing.

 

But remember that curtain odd sounds like brake pressure pump (about every other brake event and when entering the Prius) and heat recovery pump or even AC running without engine are normal for Prius.

Rust on wheel wells of Prius?

 

Maybe just a Honda thing?

 

I would say that Gen 2 Priuses rust at:
-Front bottom of the rocker panel (only if not fitted with mud guards) or front fenders where front mudguard is fitted (only if fitted with mud guards).
-Back of rocker panel (area from center of rear door back) rust from inside out. This can easily be prevented/slowed down with anti-corrosion oil spray.
-Area inside rear wheel well in front of rear wheel “dirt shelf”.
-Rear suspension
-Floor pan and underbody backwards from rear seat area.
-Pretty unimportant things in the underside. Those only matter when you try to remove them or something attached to them for some work…

 

When I was looking for a car, I found it useful to look at Carfax records to see to which dealers people were taking their cars to get maintenance & repairs. I ended up finding a pretty good dealership that way. Also, at least a couple dealers in my area have abandoned the traditional commission salary from salespeople, which theoretically makes them less likely to push shady deals. But of course, your mileage may vary.