[oceanview]

all modern cars have them. and the data is integrated into the engine management and airbag computers.

[William Terrell]

They have input and output ports. Yes, they can be disabled, and without disturbing ohter functions. The device may look like a lump of "doin' things" to you, but it looks entirely different to someone who has the hardware and software schematics and knows what he's doing.

I'd be surprised that there weren't already someone who had the technique down. As more of them hit the road, the disabling will become a valuable service at a good price.