Black Ops' most infamous killstreak, the RC-XD, has popped up in Call of Duty: Warzone ahead of the launch of Call of Duty: Black Ops - Cold War. These little explosive bastards can't be purchased from Buy Stations like most killstreaks. Right now, they can only be found by completing a special contract in a private match or practice round.
If you want to check it out for yourself, it's pretty easy. Just load up the Warzone Practice Match mode and, as you're flying in, look for the contract on the map with a radioactive symbol (if this is your first time launching practice, it might not show up until your second run). You're looking for a contract called Detection. Starting it will give you a special heartbeat sensor that instead tracks radiation. Follow the signal like you would a heartbeat and it'll lead you to a special loot crate containing the RC-XD.
Once you fire up the bastard car, it controls about how you remember from the original Black Ops: clunky, but powerful enough that it hardly matters. On top of dealing a bunch of explosive damage (enough to kill a standard bot instantly), the explosion leaves behind a toxic cloud similar to the gas grenade effect. Eagle-eyed fans will also notice Warzone's version of the car is modeled after Frank Woods' pickup truck that keeps flipping over in those Cold War trailers.
As one of the first elements lifted directly from Cold War into Warzone, it's worth noting that the Warzone RC-XD and Cold War version look, sound, and feel different. Even though every Cold War weapon and blueprint is coming to Warzone, as two games with different engines and teams, we shouldn't expect everything to translate seamlessly.
Why the secrecy with the RC-DX? Well, to drum up more excitement for Cold War, for one. Infinity Ward could also be keeping the killstreak out of normal matches for now so players can test the car and see how it performs. I noticed the car had a real tough time on uneven ground like the Quarry railroad tracks, so it might need some tweaking.