Fisticles is an expansion that gives more nuance and depth to vehicles in FIST. Think of it as The FIST And The Furious.
The PDF is 7 pages, with a layout that mirrors the core book's style perfectly.
The biggest change Fisticles makes is giving vehicles stats, which are rolled instead of the driver's. Vehicles also have upgrades, tools, and frames, which give them roughly the same capabilities as an average character.
Per the author's notes, this is intended to give the PCs a single shared super-vehicle, but it can also be used for a more car-centric game if everyone takes their own vehicle.
The actual upgrades, frames, and tools lists are well-designed, useable, and weird. There's also some neat mechanical tension in choosing either to leave your vehicle in the repair bay for the duration of your next mission, or take it hot into the next op with missing armor and hp.
Overall, this is a really solid expansion if you want to add some more vehicle-oriented depth to your FIST game. And if you've been dreaming of running your own Fast And The Furious TTRPG, this may be especially worth the look.