This achievement can come through natural progression, but can also very easily be boosted using a fast car with good grip.
What you will want to do is select a decently fast car with the best grip possible. Now you'll want to drive back and forth on the highway that links Montellino & Sisteron. You can view the video below for more exact details. While driving back and forth, you'll want to maintain a high rate of
speed and get as many
near miss skills as possible. Try to avoid drifting, trading paint, air, or wreckage as these are risky during a skill chain on the highway.
As you begin this method, you'll want to bank your skill chain decently early, but as you unlock more perks and gain confidence feel free to bank at a higher and higher skill chain.
In total, you will need to earn 65 skill points while equals
6,500,000 skills chain points! After unlocking your final point, the achievement will unlock.