When they begin the street race, the Trans Am shoots flames out the back as though nitrous was already activated, but in the next shot, the flames aren't shooting out the back until nitrous is activated.
When the Trans Am is beginning the race, it has a customized exhaust system with nitrous activated, shooting flames out of the back of the car. When it flips in the air, it has a regular exhaust and no nitrous activated.
The race between Mr. James Brown and the Devil starts in front of the Four Queens and the Fremont Hotel. They pass both hotels several times before they make it out of Las Vegas onto the two lane road.
The race begins in the direction where the cars are driving past the Four Queens starting at the "F" and moving towards the "S". Later in the race as they pass the Four Queens, again, the are driving starting from the "S" and moving towards the "F".