I use the under dash manifold with the single left hander that comes in the kit. The vents look like those in post #3. It could be low air flow alright because I do run the fan speed pretty low. The whine on that fan grates on my nerves once it gets cranked up toward half throttle. (I'm weird that way though, whiney noise can bug the crap outta me. Good thing I didn't have kids
)