Dude, did you manage to sort out your car? From my experience i did all the same as you. Changed coil packs, Valve cleaning, cam follower, spark plugs, fuel filter, fuel pump and then i pulled out the injector that was misfiring and sent it for a service. They stripped the injector and replaced all the seals and internal sivs and did testing. Apparently the injector never missed any pulses. Put it back and i was frustrated all over again. I was truly stomped. I was :mad0259: so i went to VW and bought a single injector, Slapped in on and presto. Turns out the when they tested the injector there was never any heat around it. For some reason it only misfired when the car hit its peak operating temperature.
Well that was from my experience, good luck!