RF jamming ?
Since when is that supposed to be an issue ? Sure, it'll work the first day or two, if the company was stupid enough to use a WiFi router for all its networking needs, but somebody's bound to notice that the jamming starts when a given van is parked not far away and when they do, the cops will be bringing down that attack venue pretty quick.
Internet vulnerabilities are dangerous because they are (almost) anonymous, overwhelming, are hard to block when they start and can come from any point in the world, which (in most cases) immunizes the attacker from judicial oversight. So it's easy, carries almost no risk and requires next to no physical effort.
RF jamming needs physical proximity to the target, which then forces the attacker to contend with real-life covert activity requirements. Not to mention that a van has somewhat more complicated temperature-control issues, and an idling vehicle staying in place for hours at a time is going to garner attention.
I file that the Unlikely Attack Venue folder. Especially since a simple Ethernet cable is all it takes to thwart the attack completely.