A-Pillar? These cars have a great big dash, I have seen people put speakers in it before. But I've never seen stock speakers in the dash. There is a pair of tweets in the a-pillar one on each side. Not even Crutchfield list replacements for them though. This is what I did for mine.
I put a pair of Pioneer Speakers in. Used the cabin filter replacement howto at the base of this board to get the panels off. Very easy job.
Was a bit tough to find the +/- wire colors for the speakers (lots of ambiguity out there). I went with the striped wire as the negative and it sounds great! I did have to extend the left side speaker wires, as when you mount that one the wire tabs are rotated a few inches up and there was barely any play in the stock wire.
I also just unplugged the tweeters. From what I gathered, these new speakers take care of that range also, so I didn't want any trouble from those tweeters later. I taped the connectors up securely to the frame to make sure no rattling would occur.