Why does the BMW X3 loose Value So Quickly?

I was looking at some BMW X3 and i found that after only 3-4 years they loose almost half their values. As opposed to the RAV4 it only losses about 20-30% after 3-4year? I feel that if i buy a used X3 (which is all i can afford) I'm gonna be throwing my money away.

Any Help is MUCH appreciated!!