So your saying:
It started missing, you replaced the coil packs and it fixed it.
It started missing again, you replaced one coil and it fixed it.
It started missing again, you put injector cleaner in, it fixed it.
It started missing again, you replaced the plugs, fuel filter and one coil and it fixed it again.
And now it's missing again? For starters, stop walking under ladders with black cats on them carrying mirrors...
1. With the car idling and missing, does spraying A SMALL amount of aerostart in the intake or vac line temporarily stop it?
2. Have you tried taking the coil cover off, and disconnecting them one at a time to find the miss, then moving the suspect coil to see if the miss moves?
3. What fuel do you run the car on?