Another thread reminded me of this, and it's something I've encountered a whole bunch but obviously I've never seen how it actually plays out.
In my experience, here's how it goes down: guy in a van drives up at a gas station or in a parking lot, acts real friendly, says he sells speakers or whatever and ended up with extra inventory, has to sell, yadda yadda. Opens the van door, he's got a set open and two other boxes that appear to contain the same thing. I say I don't care, have a nice day, he insists he'll take just about anything, eventually I say, "Dude, I know it's a scam," and he rolls his eyes and drives away.
What would happen if I actually believed him? Are the boxes full of bricks? What if I said, "Sure, I'll give you the $200, but I need to open it first to make sure it's legit." Would he just say forget it and drive off? Are they actually selling speakers that are stolen or counterfeit? And if not, who the fuck falls for this when it's so common? I once had three different teams approach me on the same day.
I always just want to level with the guy and ask him exactly what his angle is, but I don't want to risk his buddy popping out of the back and whacking me with a tire iron or something.
About 15 years ago a neighbor of mine bought one of those and it was a complete piece of shit system. 
Yes. Horrible quality. Amp has no power and I belie all the different range speakers are the same meaning the highs and lows are two if the same speaker .
Some of the systems have been known to burst into flames. Basically the cheapest of cheap stuff.
The scam has gotten more sophisticated over the years, there are now fake company websites complete with fake review links out there to aid in the scam.
I forgot what podcast it was where a guy talked about doing it. He said the scam is just shitty quality speakers. Because most people won't or can't do anything about it. 
The boxes will most likely have speakers in them; low quality, shit speakers. Some scammers even have somewhat legit looking websites for these cheap speakers.
I see this type of thing a lot, especially at Highway Service areas.
It's sony guts
Holy edit screwed up the spacing.
Watch out for these names. Some sound like known name brand audio companies if you aren't paying close attention.
Accusound (Not related to Accusound Australia nor the Accusound speakers made by Audiosphere in Canada)
Acoustic Monitor, Acoustic Studio Monitor 3311/3312, Acoustic Response, Acoustic Image, Acoustic Lab Technology, Acoustic Reference[12][13]
Advanced Sound Technologies (AST)[13]
Afinity[14][dead link]
Alumen Projection a-700[13]
Audio Resource[15][unreliable source]
Audio-Tech, Audio Tech Pro[13]
Audiofile[12][16][17]
Bach and Odin or Bach & Odin new scam "brand" late 2011 trading off B&O Bang & Olufsen .
BSS - Brendle Sound Systems[18][unreliable source] (No relation to BSS Audio, part of the Harman Pro Group), also Brendel, BrendelElectronics[19][unreliable source]
BTS System - Innovative Sound and Bass http://www.bts-system.com/
Bjorn and Wielder[20]
Camelot Audio[15]
Carlson Audio[15]
Cerwin Vega (counterfeit)[21][unreliable source]
Cleo Acoustics (Singapore)[22][unreliable source]
Columbia Audio[10]
Crystal Home Theater (Not related to Crystal Home Audio)[23]
Definitive Sound Technology[24][unreliable source] (no relation to Definitive Technology)
Denmark, Denmark Audio, Denmark Optics[9][12][16]
Deutsch Akustik[25]
Dogg Digital, Digital Dogg Audio[12][13][26]
DanWave, Dan Wave[13]
Dahlton[12][13]
Digital Pro Audio, Pro Audio, Digital Audio,Digital Galaxy, Digital Audio Professional Speaker Systems, Digital Audio Skyline, Digital Research[12][13][16]
DiVinci[13][16]
Dreamland, Dream Land[10]
Dynalab (not to be confused with Dynaudio)[12][16]
Elite Audio[27]
EDS, Elite Digital Sound[28]
EKO[15]
Eurosound[15]
Epic Sound[29]
Epiphany Audio[12][30]
Genesis Media Labs, Genisis Media Labs[13][dead link] (no relation to Genesis Technologies)
Glatten Audio[15]
Grafdale[12][13]
Hauffman[13]
Hy-line Sound Electronics[13]
I-Cinema[31][unreliable source]
Icon MediaLab, Icon Media Lab Digital Fusion[10][32] (No relation to LBi Ltd., the registered trademark owners of the Icon MediaLab name)
Image Reference, also known as Martin Ash[33]
Image Research
JBL (counterfeit)[21]
Jannsonn & Fynn[34][unreliable source]
Kauffman[35][unreliable source]
Kevlar[36][unreliable source]
Kinetic[14]
Kirsch[23]
Klinsmann[37]
Lexington Acoustics
Linear Acoustik[15]
Linear Phase[16]
London[30]
Matrix Audio[13]
Mantooth Audio[13]
Marc Vincent Audio[38]
Martin Ash
McLaren [13]
Millennium Theater Systems (MTS)[13][16]
Nuance Speakers[13][16]
Olin Ross[39]
Omni Audio[12]
Optamax, Optimax[40]
Oracle Projector[40][unreliable source]
Orix[15]
Palermo[14]
Paradyme[16] (no relation to Paradigm, nor Paradyme, a audio-speaker retailer in California)
Paramax[13][14][16][39][41]
Proline Acoustic[13]
Pro-Optics, 3D Optics, 3D Optiks[40]
Protechnik[38][40][41][42]
PSD[12][13]
PurTone[43]
rölkolsen (www.rolkolsen.com)
Rothdale[44]
Samaurai[13][16]
Sondergaard (www.denmarkcinematic.com)
Skyline[16]
Theater Logic[45]
Theater Research, Theatre Research, Theater Innovations[12][13][16]
US Acoustics[46]
Vanderbach Audio
VAV[15]
Vokl Audio[47]
Volk Audio (also has a projector branch known as Volk Cinema)[48]
Wahldorf Home Theater[49]
Xtreme Home Media
Boxes are not fully of bricks.
They are selling some of the lowest quality speakers around, and acting to make it look like you are getting a deal on some high quality stuff.
Basically, they act like they are selling you "hot" equipment at the super steep discount that usually comes when buying stolen merchandise.
In actuality, it's not stolen. It's legitimately sourced bottom quality SHIT.
There's not actually anything illegal about it at all--it's just unethical as fuck.
http://en.wikipedia.org/wiki/White_van_speaker_scam
They tell you that you are getting $1,800/pair speakers for $200/pair.
In actuality, you are getting $50/pair speakers.
I bought a pair 17 years ago still work great today
MMAHAWK - I bought a pair 17 years ago still work great today
I did too...I think I paid 150$ for a pair of nice looking home speakers. They still sound great.
I wont lie though...as soon as I bought them, I called a few stores and they laughed at me. I was sure they were going to blow every time I used them.
10 dollar drivers X 3, 2 dollar crossover, 15 bucks worth of MDF, hot glue, staples and either carpet or paint, 3 dollar fancy plastic emblem.
A crappy box, stuffed with crap, and slathered with a nice crap coating.
http://www.insidebayarea.com/trivalleyherald/localnews/ci_13032102
I like the oven door sold as flat screen TV scam much better.
Lux Fixxins -Gforce - http://en.wikipedia.org/wiki/White_van_speaker_scamThere truly is a wiki for everything
They tell you that you are getting $1,800/pair speakers for $200/pair.
In actuality, you are getting $50/pair speakers.
Awesome
Yeah, seriously. I wouldn't have even thought to check wiki.
I could have googled, of course, but I was curious to hear people's experiences.
Have never seen this in person, just the random cheap steak truck that pulls up in your driveway trying to hard sell you.
I encountered the EXACT SAME DUDES when I used to live in Orange Country. At the time, I didn`t know how the scam would have worked but I smelled something fishy and I didn`t exactly need a speaker so I didn`t fall for it.
OP- did this happen in Socal?
I had this happen to me once and the guys even had the speakers in some magazine ad.
They quickly flashed the magazine at me.
I applauded their tactics.
I worked doing this back in 1997. We had to sell the speakers for at least $150. Anything above that is what we would keep. Would also get a bonus if we cam back with an empty truck. Usually would head out with around 16 pairs of speakers. I live in Philly and we would drive as far out as Harrisburg and then work our way back stopping at mall parking lots, gas stations, etc.