How does the driver side unlock work, I don't have the factory keyless entry, I am curently trying to install an alarm, when I press the unlock button both doors open. Is there anyway that I can set the alarm that when I want to unlock the door it would just open the driver side and if I want to I can press the unlock button again to unlock both of the doors.

Not too sure about that. But what I can tell you is that my factory alarm system always unlocks both doors when the button is clicked. Never looked into doing it the way you are talking about.

1999 Eclipse GS
Built motor
Hahn 16G Turbo w/ FMIC
Hahn Stage 5 Portfueler (270's & 500's)
Zeitronix Zt-2 wideband w/ 3.5bar MAP
3" SS Turbo Back
CM Stage 4 Clutch and Fidanza Flywheel
Baer Big Brake Kit

I thought the factory alarm came with that option.

If I remember correctly they both use the same wires. They are not wired sepperatly from the main harness. They are on whats called a central door locking setup. 2 locks one wire.

Is there anyway that I can seperate the one wire where I have both unlock seperately?

If you run a seperate wire for the passenger door and remove it from the factory wire then it will be on its own. but it will also not work if you hit the unlock button on the drivers interior door. its a win lose situation.

I read that some of the cars that came with keyless entry had the driver unlock, I wonder how the wire is with those car.

Keyless entry is set up on a completley different wiring system. The locks are wired seperate from each other.