they ask for the code for red-light cameras and speed cameras. Some company is selling a piece of hardware that's purely and completely designed to screw you, mr(s). average citizen drving down the road and if they can jigger the results with funny code you are going to be nailed to a cross and burned (or the legal equivalent).

If they have nothing to fear, they have nothing to hide (where have we heard that before)...

In any event, if you are liable for damages or punishment, you have a legal right to see the evidence against you and how it was gathered and that it wasn't "shaped" along the way.

p.s. if a later blood or urine test proves you are over the limit, you need to be fried anyway!