Batmobile Pack
There’s only one vehicle more well known than a DeLorean or an Interceptor. One car to rule them all. The Batmobile. Batman’s ride of choice has helped him time and again to take out the super villains threatening Gotham, so why not take a break and play some car soccer? There are so many different designs for the Batmobile too, meaning you could add multiple versions into one pack. The tumbler from the Nolan trilogy, the original design, maybe even the Arkham Knight one.
A Gotham themed arena would be a hit as well, with the bat-signal glowing in the sky above. Of course, the normal additions of flags and toppers could get a boost by adding Batman items and custom paint jobs in. The caped crusaders cars are known for doing some ridiculous stunts, and they’d feel right at home with the wall driving power boosting vehicles of Rocket League.