Anyone have advice on 1 year old tantrums?

Baby just started this craziness in the last few weeks, where absolutely nothing can change and she will start screaming bloody murder.
We can be playing and she will suddenly just start screeching and throw herself on the floor, or if I walk across the room (still within her sight) she will just begin screaming uncontrollably to the point where my ears ring. Even if I come sit right next to her and comfort she will keep screeching until she cries herself out. Same thing with car trips - they're becoming unbearable. She will be perfectly fine playing with her toys in her car seat and suddenly flip out and scream until she gets taken out of the car.
Any suggestions?