Judging by the crowds I am guessing it's race day?
To get varied shots my only suggestion would be to go to different points of the track throughout the day. As this is so difficult on race days I only ever go to the qualifiers, a lot less people and more freedom for photography.
Get to the chicanes and you can get some nice head on shots, you can also up the shutter speed as motion blur in the wheels isn't such an issue.
Hope that helps a little.
John