I seem to recall several discussions here regarding speaker placement. Some people have said that door speakers are un-hearable, there was a suggestion of placing them in your headrests, all sorts of creative stuff.
Well, about a year ago, when I first moved to Denver, I was sitting at a cafe, and a ridiculously gorgeous TR-6 pulled into the garage across the street. So naturally, I left my wife sitting at the table and went over to speak with the owner. (Whose name escapes me, my apologies.) Everything about the car was magnificent, not a concourse resto, but upgraded with every modern convenience. But one of the things that immediately caught my eye was his speaker placement.
I just found pictures of the car - take a look at where the speakers are -
Yes, that's them in the custom door caps. Pretty impressive. I have above average woodworking skills (heck, they're currently better than my auto-repair skills!), so I've been thinking about doing that to my B.
For the rest of the shots of the car, take a look here -
http://www.motorwayltd.com/restorations.htm]
Of course, custom door caps and mini speakers are on about page 368 of my to do list, so it'll be a while...

PS - Sorry the image is so large. Their image, not mine.

I've got mine in the kick panels. I love their sound and look. Of course, I've got quite a powerful amp which you'd need when the top is down.

love the kickpanels. Great place for 2 reasons. one is protection from water (which will get into even the most sealed doors), the other is that the speaker paths and distances are more equalized for much better stereo seperation, and phase.