This was a bit of a pain to unlock, but with some practice, you can get this easily.
Start a custom rally with kenya as the location. Also, set your damage level to none, as one hit with the rocks or houses at high speed will result in terminal damage (although feel free to turn it back on after getting the achievement so you can get the samir achievement.)
Choose lake nakuru as the stage for the rally and choose the fujin for your car, located under group a. After turn 3, you'll enter a somewhat straight part of the course with a slight curve. try to stay on the road and don't go off track into the grass, as you won't have enough speed in the end. If you don't reach 200km/h by the next turn, turn around and start again from turn 3. It took me around 5 tries, but once I was familiar with the track, I got the target speed.