LFS uses a Polygon defroming method also used in Rigs Of Rods (a WIP project started a year ago that has deforming bodies) [maybe a polygon may attach itself to say, an air particle] or just be a part of the car that has not been collided yet.I got this problem mosly on my old 256mbs of ram pc (smash the XR Gt Turbo. It may show up easily on the intakes at the bottom) pics show comparisons between sims
image from lfs is from my old pc