I'm still waiting for the European release and I haven't been watching many gameplay videos (to avoid spoilers).

One thing that I'm curious about is in what way enemies appear in Rage. Are all enemies positioned in beforehand so that they'll appear from reasonable places in reasonable numbers? Or do enemies spawn from more or less nowhere so that they'll show up in places where it wouldn't be theoretically possible? (DOOM 3 being a good example of that system)

Basically, what I like to know is - if I clean out and exit a room, should I still be vary of potential backstabbing from a subsequently spawned mob? Or can I find comfort in knowing that my six is clear for the time being?

Opponents generally don't "pop-up" right behind you, but areas are populated again when certain events trigger. Opponents will appear by crawling over railings (generally in a very obvious manner), but they don't jump out of closets.

Thank you Solipsisto for your informative and helpful answer!
That kind of behavior works for me! I'm a bit less of a fan of enemies just spawning over and over again right before my eyes in the middle of a room that I've just secured. Certain events triggering additional appearances - that's something I can welcome with open arms!

Cheers Spso!