In freeroam, there are various racers wandering around that you can challenge at any time. These racers are considered 'roaming', which can be misleading. Their paths are fixed, which means they are always driving around the same circuit, which is the circuit you will race them in among challenging. These racers appear as green triangles on your map, but you must get near enough to them before they will be discovered.
There are four clubs, with four racers in each club and a boss. Of the starting four racers, you must defeat each of them three times. Every time you beat a racer, they will 'return' with a stronger version of themselves. This primarily means they will have a stronger car, and their 'rank' will increase from Rookie to Pro, then from Pro to Veteran. Once they reach Veteran, they will stay that way. When you defeat each member of the club three times, it will unlock the 'Boss', who will then appear automatically on your map roaming their own circuit. You won't need to discover the boss themselves. You only need to beat the boss once.
Two clubs are Race class based, while the other two are Offroad class based. These refer mostly to the style of track you'll be racing them on, whether it be dirt or pavement. Keep a list of which ones you've faced how many times, as the in game journal, through the start menu, doesn't list individual names. The following are all the clubs, their members, and their final Veteran car level you'll be facing them on.
League 73 - Offroad Class
Nassim - Lv 200
Gearbox - Lv 209
El Coco - Lv 230
Bell - Lv 209
Boss Udo Roth - Lv 260
Hazard Company - Offroad Class
Peach - Lv 220
Leanne - Lv 270
Forrest - Lv 209
Cletus - Lv 300
Boss Holtzman - Lv 320
Silver6 Race - Race Class
Wildcard - Lv 250
Black Mamba - Lv 240
Cassandra - Lv 270
Slipstream - Lv 260
Boss Gallo Rivera - Lv 330
1% - Race Class
Jesse - Lv 340
Evangeline - Lv 330
De'Aaron - Lv 370
Lindsay - Lv 360
Boss Natalia Nova - Lv 390
Make sure you only race the 1% club while driving any version of a Nissan GT-R so you don't miss another achievement.When you approach a racer from behind, hit
to challenge them. The goal is to stay ahead of them as long as you can to get 100 points. The farther ahead you are, the faster your points raise. If you're having trouble with a race, remember that rubbing is racing, and try and spin your opponent out at the beginning of the race or shove them into a rock and speed away. Otherwise, just outrace them.
You likely have found most of the racers through the course of the game. If you find you're missing any, refer to the album below. The images show the location of all roaming racers. If you're looking for one, go to the spot on the image where they're shown to be at, and park your car and wait. Eventually they'll drive by and be 'discovered'.
https://imgur.com/a/NS74XHappy Hunting!