There is clicking coming from the rear of my car and I came to the conclusion it was the axle shaft that has a TSB, I took them out cleaned them with brake cleaner and then applied lock tight which is supposed to work because I didn’t have any grease on hand. I did this and the clicking still persists. I don’t think it’s as loud but still audible. It almost sounds like there’s a plastic bag blowing in the wind. Also, the sound is most prevalent when going anywhere from 40-50 mph. Is it the axles or axle bearing?

 

Wheel bearings will typically get louder when turning, as the weight shifts onto one side (ie left turns loads the right side wheel bearings more, thus they get louder). Wheel bearings are a common wear item on these cars. Axles seem to be reliable for the most part.
Z1 makes an upgrade kit that includes both axles, rear hubs, and rear wheel bearings for a decent price if you decide to replace.