Seen this happening to often, especially when I watch twitch streams like Smoke, they are constantly getting to animation issues which seriously affect the visuals and gameplay.

Was just about to make a ticket about this.
The FPS after the latest Stable patch (1.04) has completely tanked FPS for me and others, resulting in us having to turn our GFX setting down. But, it seems like Ambient Occlusion is the root cause after this update which is tanking FPS from 100+ to 30 or below.

It happens when you near ~80ish meters of the vehicle.