not a great deal in the end
on the old falcons they had a dedicated cop cluster
that was used so it had digital speed readout and peak speed save / recall setting etc
nothing "important" and it's not a "cop chip" tune either
but they had to swap it out when they sold it as a normal car
ie a pain in the ass, but back in the old days
these days its just a toggle setting
you can turn police mode on and off on any ba cluster via the ODB port
in fact, you can change the whole car, including remapping via ODB port
on the BA
when you enable police mode
the cluster simply shows digital speed in km/h (and speedo dial) and has a top score / speed recall feature
normal BA cluster has like fuel economy on avg fuel etc
this is all disabled in the police mode to show you digital speed read out (and speedo dial)
theres also some other trick to make all the lights go off in the car
like the interior ones again, nothing special