That's what beatmaniaIIDX uses in its shaker platform. It's too cool. No, really, it's freaking awesome. I hadn't thought about using one in a driving cab, but it should be neat. 50W is plenty of power to massage two players standing on the stage of IIDX, so I'd think it should be more than enough for a driving cab.
It has a resonance around 40Hz or so, and it really hits big time at that point, but it's good down to about 20Hz or so before it drops out. This is lower than most small subs (and even some larger ones), so it can complement even a system with a sub. Just be aware that some cheap amps can't go that low without rolling off substantially. You could potentially compensate with a pre-eq stage if necessary.