I've shot Indy Car racing for a number of years.
It's relatively easy to get great shots of the cars flying past. It's a bit more difficult to get good shots of the drivers with their helmets off.
Part of the reason for this is the limited access to the pits area and the number of obstructions between you and the driver... often just the number of people trying to talk with the driver makes it hard to get a good shot.
This year at the Honda Indy in Toronto I didn't have a press accreditation but was invited to a friends suite area. As luck would have it this elevated area had no fence between me and the cars plus the real bonus was a great view of the Pits area.
Movement from suite to suite was limited but I was stationed right in front of Paul Tracy's team and he's always the hometown favourite in Toronto.
I just had one camera with me since I wasn't really working, a Sony Alpha A900 with a 70-400mm Sony lens on a monopod. Besides shooting the race I was able to get a couple good shots of Paul with his helmet off without having to fight off the other photographers in the heat while enjoying a cool one in the suite.