Red button

The Hyperdrive Mode, (also called auxiliary mode) enters hyperdrive once it is pressed. MiB rules state you should never press this unless it is an emergency.

Men In Black
It first appears when Agent K tells Agent J not to touch the red button. It is later seen in when K and J are chasing Edgar The Bug. K told J to press it, which sent it into hyperdrive and bypass the traffic in Queens tunnel by driving on the ceiling of the tunnel.

Men In Black: The Series
The red button is seen in various episodes of the animated series.

Men In Black II
Some point prior to 2002 and after 1997 the hyperdrive had been modified. This meant the Automatic Pilot had no control over it, and it had a gaming remote instead of a steering wheel (which K rather disliked)

Men In Black III
The red buttons do not appear in the third film, but they are mentioned by Agent J in 1969 when Agent O introduces K and J to the jet packs. J the Jet Packs aren’t in the future for a reason. K says the Red buttons aren’t in the MiB cars yet.