My suggestion for 2AA is the iTP SA2. The reason I say this is that it will still be able to hold low mode with new Energizer L91 lithium batteries. You see the problem with 2AA form factor is that the forward voltage drop of an LED is around 3.25V..........which is about the same voltage as brand new batteries. In fact the lithium's might be just a little higher in voltage and so since most 2AA LED flashlights just assume that most of the time the voltage of the batteries is below the Vf threshold, then their circuit regulator is a boost type. Then if you have a battery voltage slightly higher, then you lose regulation on the low modes until the voltage of your batteries drops down.
Well, that kind of bugs me so I've stuck with 2AA lights that don't have this issue. Lithium batteries are the best for cold temperatures and for being able to leave your batteries in your flashlight without worrying about them leaking acid like alkaline. To me a 2AA emergency light in the vehicle needs to have Energizer L91 lithium batteries.........especially if you are not using the light very often. Otherwise, I'd use Eneloops and then most any good 2AA light will work.