The Special Edition only modeled a single X-wing fighter for its CG shots. All the CG shots are Red Two (Wedge). This can be seen by the wing markings.
The Alliance pilot helmets in Star Wars have comlinks on their left side, or the screen-right side. They do not have them on the other side. Yet, this is made all the more confusing with the use of reversed footage in the final battle. Watch carefully, and you’ll spot it numerous times:
Red Leader: "All wings report in."
Wedge: During the opening turbolaser barrage, there’s a dramatic profile shot of Wedge.
Red Leader: "I copy, Gold Leader." (this was one done to have Red Leader and Luke look in the same direction)
Red Leader: While Luke says "Red Leader, we’re right above you."
Red Leader: "Stay there, I just lost my starboard engine, get set up for your attack run."
In case you really wanted to know, here are the astromechs assigned to the Rebels. Red Leader has a cool red and black R5 unit (1), Wedge appears to have an R2 unit, (2) possibly with red trim. Biggs has the droid identified as R2-X2. You can’t see it in the film, but photographs show it. Porkins has a white R5 unit.
The dent on Threepio's head moves around, thanks to reversed footage. Watch for it.
Watch carefully, frame by frame, on Gold Leader’s first shot, where he reports in to Red Leader. The Y-wings seen flying in the background disappear in the last frame (inset), before the scene cuts to Luke. Later in the movie, watch carefully, frame by frame, as the Y-wings dive on their attack run. The "top" Y-wing of the three disappears on its dive.
A fun thing to spot: in the first shot of the Imperial gunnery station, the gunner directly beneath the laser barrel is covering his ears, even though he’s wearing a helmet.
I’ve always enjoyed overenthusiastic extras. Watch how fast some of the Imperial officers run aboard the Death Star during the battle. It’s quite funny.
Watch the hallway as Lt. Tanbris tells Lord Vader how many Rebel ships there are. There is a red R3 unit (clear domed) and a power droid wandering by.
In the profile cockpit shots of the X-wing starfighter, you can see the engines, but you should also be able to see the wing and guns.
The first Rebel pilot to be killed by TIE fighters has the coolest red and black helmet. Just had to say that. Oh, and he looks like Bob Saget or Harold Ramis. (He's not, though, so don't go spreading rumors, now, okay?)
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Red Alert Lights
A subtle effect, when Vader and his TIE pilots walk to their ships, check out the red alert lights on the walls.
The dramatic shot of the aerial approach of the Death Star trench is a beautifully executed special effect trick. When at the highest altitude, the trench is a painting. The camera zooms in, and there are several lightning cracks as turbolaser fire buffets the approach. Watch the last flash as it covers the painting’s replacement with the miniature. It such a cool effect, it’s used again during Luke’s approach.