My car is running an all active system. I went this route due to the ability to mix and match drivers to my liking until I found a setup that I liked the most. You don't have to build a set of passives with each new setup; you have the flexibility to quickly change crossover points and slopes until you find what matches your tastes and compliments the drivers the best. If you've ever dealt with car audio you know it's a beast of another world and that driver location/installation is a HUGE factor. And you'd also know that each time you change the location you also need to change settings.
From there, it's also about choices; for varying music I find that I sometimes like to change my x-over points (I don't care if this is 'right' or 'wrong'). Very rarely do I do this, but when I want to wail, in order to protect speakers from distortion it is necessary. My system was built to take some serious power and dynamics and IMO, active is the better way to achieve this.
Having said all that, I will not be going active in my home setup. Quite honestly, the cost is too much for me to dedicate 200w/channel to a set of 3-way towers. Luckily, there's at least HPF on most any receiver; as it seems if I ever do change x-over points, it's typically between the midbass and the subwoofer.
