Quite the same thing happened to me yesterday. I was making my
way to TPE from sengkang. The slip road that merges with the
expressway has two lanes that merges into one lane closer to the
expressway. I was on the left side, there's this Civic behind me on
the right side.
From my rearview mirror I know he wanted to overtake me, maybe
he can't stand getting stuck behind a red-plate Picanto. At the
point where he tried to overtake me the two lanes are nearly merged
into one lane already. I even shifted my car to the right a little
to try and block that little bastard, yet he squeezed passed me and
we were so close to clipping each other's car. My blood was boiling
like mad at that point so I horned and flashed high beam.
Once I was on the highway I chased him and purposely cut right
in front of his lane and brushed my brakes a few times just to
teach that little SOAB a lesson. 
wow , your blood boil like mad, lol, that is normal for a young
man.
but we must learn to see the bigger picture ,,,that is our
safety, thk.