Thought I would jump in here - I found a bunch of fob programming instructions:
To program the key fob for the early model BMW 3 series including the 318 you have to
start with all doors, trunk and hood closed.
(these aren't mine, they were all found here
http://programcarremotes.com/bmw/bmw...e-programming/ - I think they have other model years as well)
There are several different methods to try for the BMW 3Series so you may have to try more
than one. TIP if one method fails the first time, try it a second time before moving on
to a new method as they can be tricky to get the steps right
METHOD ONE
Step one Open the Trunk
Step two get in the drivers side of the vehicle and close the door
Step three insert the key into the ignition and turn it ON and OFF five times ending in the OFF position.
Your car should indicate that it is ready for programming by emitting a loud chirp noise.
Step four open and close the drivers door (but stay in the seat)
Step five press any button on the key fob.
The light should flash indicating that programming has been succesful
Step six repeat steps three and four again for other remotes your wish to program.
Step seven when you have finished programming key fobs, leave the door open, get out and close the trunk and then close the drivers door.
Your car should indicate that it has completed programming mode by emitting another loud chirp noise.
METHOD TWO
Step one get in the drivers side of the vehicle and close the door
Step two insert the key into the ignition and turn it ON and OFF five times ending in the OFF position.
Step three remove the key from the ignition and hold down the UNLOCK button for 15 seconds while pressing the LOCK button three times rapidly.
Step four release both buttons
Your car should indicate that the key fob has been programmed by cycling the door locks.
METHOD THREE
this method requires at least one working key fob. If it doesnt work the first time switch the order of the keys.
Step one get in the drivers side of the vehicle and close the door
Step two insert the key into the ignition and turn it quickly from ON to OFF. All the rest of the steps MUST occur in 30 seconds or less.
Step three remove key #1 and hold it up near the roof on the drivers side by your shoulder (this is where the reciever is located)
Step four hold down the UNLOCK button for 15 seconds while pressing the LOCK button three times rapidly.
Step five release the unlock button
Your car should indicate that the key fob has been programmed by cycling the door locks.
Step six repeat step three, four, five fast for key #2.
How to program a new key fob 
1996 ti key fob 
Key fob 
Linear Mode
