Zandvoort is one of the most challenging tracks in the entire game. You're nearly always climbing, or falling, sweeping one way or the other around the sand dunes. Every corner on the track is worth of comment- with the fast sweeping sections at the "top" of the track (on the right-hand side of the map) being notable for their very indistinct braking and turning points, but what we're looking at here is the part that often causes most trouble, the very sharp right into a hairpin left that seems to have escaped from a rally stage somewhere.
You'll approach the turn near max speed in 6th gear, if you've had a good run out of the previous turn. Keep the car well over to the left and follow the gentle left sweep of the road. There's a small brow that obscures your view of the upcoming turn, so keep an eye on the marker boards. You want to be on the stoppers a bit before 100m, and turn in where the line that's been laid down shows. You should still be on the brakes on turn-in, but off them just as you apex the right. You need to be as close to the kerb as you dare, but don't hit it, as it'll upset the car and you need all the control you can muster.
Smooth driving goes pretty much out of the window here, you've really got to throw the car at the left turn, again staying off the kerb. You'll be in 2 nd gear at this point. The hard part is over, just smoothly exit the turn now- run out to the right, and get ready for the final two super-fast turns to complete the lap.