i have had tweeters in pillars before and its not bad of a job pretty straight forward but i found the tweeters being closer to the components sound better, to the type of music i listen to. Also i have read on audio forums that tweeters should be close to the components for optimum quality.
I used to have tweeters mounted in the pillars on another car but they did not sound that good, from that experience i would not do that again. I saw a red polo at J.A.E last year, the lad who had it was an audio installer, he had installed the components at the bottom on the pillar in a fibre glass surround against the windscreen and tweeters in the pillars that was awesome!!
But where i live the stuff would get nicked if it was so blatenly on display. I have had ice nicked out of this golf before!! which was a bummer
