Stealing cars
A Slim Jim or a smashed window, and reportedly a key cloner for anything worth taking.
The Extended Look shows a prompt on an approach to a parked car offering a Slim Jim or simply putting the window through. One is quiet and takes time. The other is instant and makes a noise in a game where noise is now evidence.
Why a small change is a big one
Car theft in Grand Theft Auto has been a single button since the first 3D entry. You walk up, you press, you are driving. It is the defining verb of the series and it has never had friction in it. Adding a choice, even a two-option choice, changes the texture of every unplanned getaway. Standing in the street working a Slim Jim while a description of your face is circulating is a different experience from pulling a door open and going.
Reporting on the same footage describes a key cloner being required for more valuable vehicles, which would put a tool requirement between the player and the best cars on the street. Rockstar has not confirmed that, so treat the cloner as reported rather than shown.
How it connects to everything else
A broken window is a damaged car, and a damaged car is a more identifiable car under an evidence-based wanted system. Since larger weapons travel in your vehicle rather than on your person, the car you steal is also the car carrying your loadout. Losing it costs more than a walk.
What is not known
Whether tools are consumable, purchased or unlocked has not been shown, and neither has the failure state. Alarms, owners and passers-by all exist in Grand Theft Auto already, and none of them have been demonstrated interacting with this prompt.