I've already once done a double-din install in my car, everything worked fine but I've since wanted to clean up a few things and further refine the install to my liking, such as adding additional buttons to my steering wheel for hands free calling etc, but that's completely unrelated.

What I want to know is this: Will adding 2 microphones via a 3.5mm splitter be a feasible option? Will this even increase the amount of sound picked up? Theoretically dual mics = more sound picked up, but since they're being fed to a single channel input would this truly increase anything at all? My previous setup had a good location, but some people said I sounded faint, no distortion, no weird noises or anything like that, some people just had difficulty hearing me, so I was simply wondering if dual mics would alleviate this, if at all, or will I have to pursue alternate options in order to remedy this issue?