In the Season 1 episode of CHiPs entitled "Cry Wolf" (disk 5 for those of
you that have the series) a guy calls the CHP and reports false accidents.
In the first false accident he reports, the stock footage from Emergency
of
the squad and engine leaving Station 51 is used. I clearly recognized the
same squad and engine from Emergency and the station. However, in a major
blooper, once the engine and squad drive up to the location of the report,
a
different squad and engine that isn't the same one seen in the stock
footage
is used, and the number on both are 519.