Drifters have a corrosive ranged attack that is devastating to vehicles. They can also be killed by staying out of its range and shooting it, e.g. the homing missiles of the Monster, in order to avoid its corrosive projectiles. The raised highways provide a good vantage point to exploit this strategy.
They have three glowing orbs around the base of their body. Shooting these will result in a critical hit and the orb exploding. These critical hits cause massive damage, around 1/4 of the Drifter's health, thus destroying these orbs will severely weaken it. The back side of the abdomen can also be shot for critical hit damage if it is visible.
They will jump towards pedestrian targets, and will stomp on the ground to damage victims at close range.
They are weak to shock weapons.
Their abdomens are vulnerable, like those of spiderants.
About five full rocket shots (all three rockets hit) from a Monster vehicle will kill a Drifter. To gain weapon proficiencies quickly, use Racer/Monster vehicle rockets to wear the Drifters down to a sliver of health from far away, and then jump out of the vehicle and finish them off on foot. (Vehicle rockets tend not to destroy their weak points. Using a semi- or fully automatic weapon has a good chance of hitting one of the critical points, causing an instant kill). A level 60 Drifter is worth 10,000+ exp on foot.
A fully upgraded Radiance skill is very effective for Lilith to use against them.
It is extremely hard, if not impossible, to run one over.
The Lancer's shock turret can be very effective against Drifters. However, the turret must be manually aimed at the main body of the Drifter - locking on causes the turret to fire through the Drifter's feet, doing no damage.
A Double Anarchy SMG or a rapid-fire shotgun is very effective to hit multiple critical areas.
If characters plan on looting their corpses, they should do so in haste, as more Drifters will pull themselves out of the ground, keep a very close eye on the compass for red dots and either have the appropriate weapons or make a bee-line towards a vehicle. Furthermore, Drifters are almost completely silent before attacking, so there's no audible warning until one is on to you.