I used to be on the Saab owners forum, but since I retired that car, I bought a 2015.5 Volvo S60 and I have discovered a few fun features, or commonly known as Easter Eggs.
1. In the S60 Sedan, if you use the actual key to lock the glovebox, it acts like a Valet. Locking the glove box disables the trunk function on the fob and the dash, so you can safely lock things in the trunk and someone else driving the car can't get into it, unless they have the physical key and unlock the glovebox.
2. If you hold down the > button on the steering wheel or dash, the radio will advance to the next station. Great for when you are traveling If you tap it, it just advances to your next pre-set station
Feel free to add other features you have discovered.