Hey man, sorry to hear about your evening.   Try not to let it shake you too
much.    It is scary out there and we have all probably had similar
experiences.    You did the right thing by keeping your cool.

If it's any consolation, I had an experience a few weeks ago that made up for
all the bad driving experiences out there.    
I was coming down a long mountain pass on my way home to Los Angeles.    It
was a one lane road, backed up, car to car, everyone was leaving the ski
resort and returning to the city.    Top speed was about 10 mph.   Anyways, a
lady pulled in the line of cars behind me and ended up rear-ending (lightly)
two cars as we all went down the hill.   She must have been on something, she
was all over the road.   When she neglected to pull over, I called 911 and of
course the reception was out on my cell.   So she goes around the cars that
she had hit, cuts in front of me, almost hitting my front quarter panel.   So
I follow her.   She couldn't get away with only one lane and all the traffic.
  It was the world's longest and slowest car chase!   My phone was out of
range so all I could do was follow her down the hill.    Finally, about an
hour later down the hill, I see a Highway Patrol coming up on the opposite
side.   I pull over the center line a bit and flicked my highbeams at him.  
He sees me and stops next to me, door to door.   I told him what had happened
and he does a U-turn and lights her up.    At this point, I am about
screaming for joy that I was able to stay behind her for so long and finally
spot a Highway Patrol.    He pulls her over, I pull over, the two cars that
she hit pull over, and two other drivers who saw how bad she was driving
pulled over.     It was a great site!    She got busted and they cuffed her.  
  When I pulled out of the turnout, I peeked over and gave a nice grin to
her.     It was revenge for all the times you say to yourself, "where is a
cop when you need one!"     
And the Passat did fine through all of it of course.           ; )
Hang in there!   One day, it all comes back to all who deserve it.