So, I have finally gotten a 1/5th scale (Losi Mini WRC) and when I paired it to the transmitter, there is a constant servo hum.... I can adjust it out, but as soon as I make a move, the hum is back. Is this normal?

Reason I'm asking is I have a 1/8th scale nitro with no servo noise....

almost all my savox servos have been noisy.

If there is no load on the servo it should never make a sound, regardless of brand. If you plug in the servo and it is sitting on the table by itself and buzzing something is wrong. Things change when it is hooked to a linkage and you start actuating it. If the car is on the ground there will be a slight friction load when you move the wheel so it is normal for a slight buzz even when you let go of the wheel. A 1/5 car is pretty big so the load is likely to be a little more.