Expanding on other solutions, here's a method to get the achievement in around fifteen minutes with little difficulty.
Once you unlock the Apostles Overlook Community Blueprint Point (SE corner of the map, north along the coast from the Byron Bay Festival) there will be an Official FH3 bucket list called Leader of the Pack for hitting 193mph in the Lykan Hypersport. The challenge is a straight shot with no need to brake ending at a speed trap. The only catch is no rewind, but I've knocked out several with a sloppy start and still hit around 198mph.
Successfully repeating any community bucket list counts towards the achievement, so complete this challenge ten total times and you've got it in the bag.
EDIT: StubaJay adds this is best done on Manual. This is also how I completed it.
EDIT: NiBium adds “if you don't want to go manual, then turn right once you start and then past the tree/bush pull a U-turn left onto the road to give you an extra 50m or so. This should be enough to negate the gear change and you'll still have loads of time to reach the end.”