[thisnametooktolong]

That is your safety switch so that you cannot slam it in park locking the steering wheel, when you are traveling down the highway. Until you get a new one you can toss the old one over your shoulder. AS long as you don’t play with the shift lever when you are moving you don’t actually need it. I compare it to the auto shut offs they place on lawn mowers. As long as you have two functioning brain cells you don’t need it

And Yes GM has a problem with them because they also do not allow you to shift out of P without your foot on the brake. That means a lot of old drivers place a lot of ware and tare on the plunger because they forget about the need to step on the brake. (not to mention the damage done to the plastic bushings on the shift lever itself)

Edit: I mispoke, that plunger is to keep you from locking the wheel by turning the key off when you are not in park (woops) but the i was correct about the brake interlock