The aforementioned online play trick certainly works. Unfortunately, if you only play solo against AI, there's no way to cheese this that I know of. Time limits mean your opponent will be eliminated before you reach the finish line if you idle a second controller. Rubberbanding makes this an unreliable achievement, but Area 41 seems to be a track where it's more likely to finish a race with a 3-4 second advantage on normal difficulty AI, a timeframe that allows you to turn around and still win. If you are grinding all the achievements of the game, chances are you're replaying the shortest and easiest Grand Prix, GP1 with all cars. This one has Area 41, and I had various races where my gap was big enough to pull this off.