Thanks guys for the responses.
@boost3d: I've been contemplating MHD since the issue first occurred but my DME falls within range of DMEs that are locked and I didn't want to waste money on the cable if I wasn't sure.
https://play.google.com/store/apps/details?id=com.mhd.flasher.n55&hl=en_ZA
I'd appreciate it if anyone in Durbs with a K+Dcan could help me confirm this

raise: ?
Also my car is manual(thanks will add that to initial story).
@M@rk: my tuner bench tested as well as checked the voltages under the misfire conditions and said that they are working fine:dunnoanymore:.
@yuvir: In terms of the carbon build up - there was a bit but not sure if it was enough to cause a sudden misfire condition - though it could be a possibility.
The thing is guys - the car ran perfectly until this issue occurred - apart from my oil filter housing gaskets and idler pulleys change in Jan - she never skipped a beat.
No idling issues, misfires, power loss, surges, long starts etc...
I'm starting to suspect that it may just be the plugs :dunnoanymore: ...
I'm reading about instances of brand new oem plugs being defective even on this forum.
My tuner has bench tested the plugs and checked the gaps - but what are the chances that they could still be defective ?