Scheduled to release later this month around the same time as the Supersonic Fury DLC, Rocket League update 1.04 will allow you to forfeit ranked matches, giving you the option to leave without being temporarily banned for outright quitting:
FUN FACT: The next RL patch (v1.04) due later this month will add a “Vote to Forfeit” button to Ranked online matches!
— Rocket League (@RocketLeague) August 6, 2015
As well, 1.04 adds Ranked 3v3 matches, the Utopia Coliseum map, Spectator Mode, and more than 80 new country flags. The full list of flags is over here.
They also addressed issues people may be experiencing when attempting to unlock Sweet Tooth on PlayStation 4:
If you had all or most of the wins before our patch, you may need to win some again. Go for #2 w/ each [car] and that should do it.