What does that second little button do ?

[jeff m]

There are two buttons that are operated by closing the driver's door.

One is for the interior lights.....what is the other one for ?

This is a USA car if that makes a difference.

(I'm too lazy to look at the wiring diagram)

[streaky]

Separate switch for the alarm system? - Streaky

[rev-erend]

Where are the buttons ?

[L33]

Picky?