I'm running an i7 4930k @ 4.5ghz, and two GTX 680s' in SLI.
I've also been testing with several vehicles such as the hatchback C_Hatchback_01_F. The FPS drop is slightly worse however.
Overall I've tried several vehicles the problem seems wide spread. Thanks.
Mini-FPS graph also attached, first level point (no vehicles spawned in sight).
Second smaller drop is looking at the vehicles.
Third LARGER drop is inside the vehicles.