@ELM -
Right now I re-used the cap that Kia was using for the stock tweeter. I'll take a look and let you know. I don't plan on using it for long because I'm going to install a set of 2-way separates that come with external crossovers. I'm currently looking at a Soundstream Picasso Nano...
So I use to own a car stereo shop back in the days and now I just do it personally for the fun of it. Buying an EV presents a huge problem when upgrading the stereo in your car. You need an amp to get the volume levels up. Amp+EV=more power drain (not good). So I'm going to go with a class "D"...