Those are called white van sales. Believe it or not its actually a real business and thats their selling tactics.
Usually the company will hire a couple real loser looking guys, find some guy in a parking lot and say that they ordered too much stuff and are trying to sell off the extra at some super awesome price. The name brand of the speakers they sell changes every five years or so but its always the same stuff "liquid cooled titanium tweeter, extended kevlar woofer... etc".
The sales pitch is actually standard company MO... the idea being people are more likely to buy crap equipment if someone shady tries to sell them a $50 speaker that they claim has a $2k MSRP for $150 out of the back of a van or SUV.
Friend of mine actually bought a pair at cost, which was something like $80. For $80 they were ok. But for the $200 or higher asking price they are not. The shady loser guys get a huge cut of whatever they sell the speakers for over a certain price so they try to get as much as they can.
I've been hit up two or three times a few years ago. The second time I actually got to talk to the guys for real and learned how the whole thing worked.