That's because this is the near-mythical "dashboard model" . It also contains a radar detector.
If the cops pulled you over for using it since radar detectors are illegal in most municipalities, you just switched the rhythm portion on and waited for the officer with those wonderful beats playing. Worked like a charm every time, I hear.
At gigs, the radar detector could tell if the guitarist was playing too many notes, in which case an alarm went off and delivered 50 amps of pure power right to the unfortunate guitarist, sending him flying right off the stage. As negative reinforcement, it was quite effective. After a few jolts, the average reduction in excess guitar notes was well over 50%.
Can't understand why they didn't sell more of 'em...