Yes, I can see you walking up at at truck stop as you open up your trench coat. Inside is a vast array of lightbulbs, high-output shower heads, bottle rockets, and Sudafed.
Already been done on Seinfeld 13 yrs. ago. A guy with a bunch of showerheads under his trenchcoat, selling them on a street corner to get around New York City’s low-flow ordinance.
If only a three-gallons-per-flush toilet would somehow fit in there.