In Sewer Speedway, you can take a shortcut that will enable you to go faster and end up ahead of the pack. This shortcut can be reached with a speed power-up. Go into the tunnels immediately after the first part. Stay on the left ledge and look above the right ledge. You will see a hole in the wall. Speed into it and follow the pathway.

Note: This shortcut can be reached without a speed power-up. When you get into the tunnels, stay on the right ledge. When you get to the first left-hand corner, start a sharp turn left so that you are about to drive onto the left ledge. Before getting onto the ledge, jump and turn 180 degrees and land back on the bank. You will get a hang time turbo. Drive across the track and jump as you are about to get onto the right ledge. If done correctly, you will be able to reach the hole. It may take some practice, but it is possible.

When you get to the hole in the wall after the fork (you can get there by using the floor as a ramp. for details, watch Oxide's ghost), instead of going to the other side, drop to the track. This is quicker, and you may get a fruit box.