I'm finally considering changing out the stock speakers in my '01 S2000 for a component set and a amplifier. Since the '01 only came with 2 speakers, I'm trying to figure the best place to install the satellite tweeters for both sound, appearance, and workability.

Any ideas/thoughts?

 

Lots of options. I bought some door panels that had cutouts already, but my tweets are mounted about where the tweet pods are for later models. Make a hole just shy of the dimension of your tweet in each door panel, then use a Dremel to slowly take out some additional door material in a circular pattern. Eventually you'll be able to pop the tweets in for a snug fit. There should be some brackets that come with the tweeters in a component set. Use those to brace them on the back side.

If I had to make the holes myself from scratch, I would measure the distance on a AP2 door panel, then start my holes there. Start small by cutting a small X in the door, then round out the hole with a Dremel. Take it slow, and do just enough rounding out to get the tweet to squeeze through. Too much and it will be loose.

 

We can custom mold them into your A-Pillers for you. This will give you great sound at higher speeds with the top down. Plus doing it this way if you wanted to return the car to stock you can swap these out in 5 minutes, leaving no damage to your car's interior or the door panels.
You can check it out here: http://www.kineticautosports.com/A-Pillars.htm

 

A-Pillars is optimal Great reflection (glass) and right at ear level. Next best is upper section of the door (like the 03+)

I would do A Pillars if I had an 01 though.