The NB front upper control arm contains a ball joint that was not designed to be replaceable. Unfortunately, there is no aftermarket replacement ball joint that is designed specifically for the different taper used in the NB upright. This means that if you have a bad ball joint, you have to change out the whole arm.
You can tell if your upper ball joint is bad if you get a hard thump under braking or sudden cornering loads. Also, the ball joint should have some resistance to movement and not just flop around. Failure usually starts with a damaged boot that allows debris into the joint.
Cars that use NB uprights should use an NB upper control arm. Cars with NA uprights will need an arm with an NA ball joint.
This is a Moog aftermarket replacement part. It includes new rubber bushings as well as the ball joint. Ready to bolt in.
There is a bracket for an ABS sensor on the arm. That's the only difference between right and left - if your car doesn't have ABS, it doesn't matter. Right and left refer to the car as viewed from the driver's seat - in North America, the left is the driver's side.
While this part is not adjustable for alignment, we do recommend getting your alignment checked after installation just in case.