OK, I figured that this will be the culprit of my misfires under boost. I figured it would be the MAP sensor or as some of You call it Boost Pressure sensor, which should be located on the pipe coming from the intercooler to the throttle body (ETM) according to VADIS:
As you can see there should be two sensors on the pipe, but there are NONE on mine.
Here's the pic of my pipe for reference (sorry for a bad shot but I put everything back together and didn't feel like taking everything apart)
So now the question. Where's the MAP Sensor located on a 2004 S60R ??