Since I've owned the 02 X5 3.0L, the rear a/c blower has seemed extremely underpowered. Is there supposed to be a decent amount of flow coming out of the rear vents or is it supposed to seem like the flow is completely supplied by the front a/c blower. The air flow is weak out of the back vents. If anyone can let me know how their's works, that would be great. Thanks.