Car subs work well in cars because the car itself becomes the "cabinet" for it.
Unless you plan on playing in the car (or parking your car onstage) you aren't going to hear much of anything in a band setting...even if you added a midrange driver to it.
Home and car audio are completely different from live music sound reinforcement. What seems quite loud in a car or a living room (like some kick-ass home theater systems) is nowhere near enough to compete volume-wise with a live band.
To sum up my answer to your question...NO!
Unless you plan on playing in the car (or parking your car onstage) you aren't going to hear much of anything in a band setting...even if you added a midrange driver to it.
Home and car audio are completely different from live music sound reinforcement. What seems quite loud in a car or a living room (like some kick-ass home theater systems) is nowhere near enough to compete volume-wise with a live band.
To sum up my answer to your question...NO!