The game's physics are tied to the FPS instead of an internal tick system, dummy mistake, but modders made a frame unlocker anyway. Problem is, it messes with car physics a bit.
Turning is a lot faster, maybe acceleration as well, and collisions can cause much more exciting crashes. Braking is much slower, and almost useless.
The mod includes a toggle to instantly switch between 30/60 (or whichever FPS you choose), and though I started out keeping to 30fps for when I drove, I transitioned to driving at 60 regardless of the physics changes.
It's quite a thrill. Maneuverability feels rather enhanced, even if it's riskier with the lack of proper brakes. Car chases are a problem though, as those tend to include a number of scripted elements, and those can get thrown off quite a bit with the physics changes. I had a guy smash into a truck that couldn't stop in time (due to the brakes) and send it flying into a gas station, exploding it and killing a hostage the perp was supposed to take. Lesson learned. Car chases should be played at 30fps.
Most exciting car crash I'd seen though.

This is what happens when you put your physics calculations under Update() instead of FixedUpdate().