Regarding Emissions: I think a reasonable compromise to accuracy in discussing this topic in a non-technical forum is to discuss GHG (greenhouse gases, the cause of global warming -- largely a matter of C02), and smog (Nox, Sox, Hydrocarbons, Particulate matter) separately.

Some cars can approach Prius in (mpg) C02. Diesels, for instance; or the Honda Civic HX.
A growing number of cars obtain the admirable SULEV (90% cleaner than minimum CARB requirements) smog emission credentials that the Prius does.
No other non-hybrid car comes anywhere close to doing both well, while the Prius is superb in both categories. This is what makes the Toyota Prius and Honda hybrid family such a compelling alternative to conventional cars.

I imagine MPG and epa will come up. Here are the points I would emphasize:
Overall, Prius obtains the same *percent* of epa (85 - 90) as other cars, for the average driver. And like other cars, better or worse for an individual driver is mostly a measure of driver habits, trip length, and local climate. If you get 67% of epa in your current car (even if you do not know it!), you are likely to get 67% of epa in your Prius. So the greater than two-fold increase in gas economy holds true when upgrading from a current average economy car. The only difference is you know exactly what your economy is with a Prius, whereas most people were just assuming (incorrectly) that they were obtaining epa averages with their conventional car.

Good Luck with your interview!