Here is the full list of all 35 GRIP achievements.
Finish all carkour courses
Race 10000 laps in total
Destroy 1500 opponents
Destroy 500 opponents
Average a speed 700kmph+ in a race
Destroy 50 opponents
Hit Mach 1 in a race
Destroy 5 players without dying
Finish the campaign
Finish a 20 lap race
Pull a wheelie on the ceiling
Race 2500 laps in total
Destroy 4 players without dying
Win a race by passing the leader in the last second
Destroyed some scenery
Hit 3 or more opponents with a single charged RamRaider
Destroy 3 players without dying
Destroy 2 players without dying
Hit 3 or more opponents with a single Hydra
Create a custom tournament
Finish a carkour course
Race 100 laps in total
Go from 10th to 1st within one lap
Hit only vehicles with every Hydra missile in a salvo
Finish 1st 6 races in a row
Destroy an opponent
Finish an arena match
Hit an opponent with a full round of Raptor bullets
Perform a double-somersault when airborne
Finish the tutorial
Hit an opponent with a Scorpion launched when airborne
Finish 1st 3 races in a row
Hit an airborne opponent with the Scorpion
Finish 1st in a race
Finish a race