Squeak when braking

[The little red pill]

I've noticed that when braking suddenly at any speed (ie 5 mph, 10 mph) just as my cars comes to a dead stop there's a final squeak coming from one of the back wheels. It's sounds like a squeak from a spring, but it's not a spring since I've pushed down on the car to compress the springs and it doesn't make the noise. It's definitely when the car stops abruptly. It's a 2009 with only 10k miles, so I'm not sure what the problem is.
Also, I've always had a "click" sound coming from the front when shifting into park, don't know if it's the pin that goes in when shifting into park? Just haven't really heard this on any other auto trans before.
** Also, there have been no modifications ever to my car, and the wheels have not been taken off lately. Thanks for any advice!