Ok, I did misunderstand you then. I got hung up on your comment about the physics being wrong, when you actually aren't complaining about the physics as much as the lack of detail in the effects.
It actually doesn't take a lot to rotate a ship in a zero-G vacuum. Keep in mind you don't have much inertia to fight against just to reorient the ship. You aren't actually trying to move the ship against it's forward inertia, just turning it and flying straight in another direction. It's not extrodinary to think that the retro rockets wouldn't make a noticable exhaust plume. I guess I always just assumed it's there and just not immedietly visible.
Now if the viper had moving flaps and other atmopsheric control surfaces moving in correlation to it's space manuvers I would have to agree totally with you.
Geo