Looking for a 12V..servo? (don't know)

Maybe someone here can help. I want to be able to push a button in the car and have a small arm moved/rotated on a device I'm making. I guess I need some sort of 12V motorized plunger(?) device with a straight arm on the exposed end of the plunger (maybe 1-2" long) that goes in or out of the plunger thing depending on whether the switch is on or off. I'll connect that arm to the device I'm building (it's lightweight) It doesn't have to be a plunger..that's just my guess what it'd look like, a short cylinder type thing with a straight arm sticking out of one end an inch or two. One end of the cylinder bolts to something solid and when the 12V hits it, the arm extends out. What the heck am I looking for?? Anyone know? and know where I can find them?

if you dont need a whole lot of travel you can get a small push solenoid (but travel is usually only around .25 - .5 inch). you could use a door lock actuator. if you are looking for a large travel you can look at linear actuators (not cheap)