It's a HEMI!
This is pretty interesting but I suspect using a traditional guitar amp would blow the speakers, as they were designed for car stereo not guitar amps. (And I've recently learned something about blowing up your kit, as I fried my Fulltone Fulldrive II last night. Verdict: it sucks.)
If you were to use it as a monitor for a software amp modeller, however, I'd be interested in checking it out. Especially if you had those piezo electric pickups to do that acoustic modelling, then this speaker would eminate radially just like the real thing.
Or you could just play an acoustic guitar.