You are still confused:
Bump mapping by itself does not make holes. That requires mutiple channels of textures ( bump, specular, diffuse as minimum - as well as can be done nicely with light mapping and ilumination)
In the case of LFS - I would say nothing more than a Specular Map is needed for track surfaces anyhow - and possible using the generic bump mapping in conjunction "only if it is optional".
BUMP MAPPING:
^-- LFS can implement this easily without switching to a newer version of directX.
Parallax Mapping (Offset Mapping)
^--- overkill in a racing sim
Steep or deap Parallax Mapping (Offset Mapping)
In this form - the normals texture can cast raytraced shadows upon itself...
^--- If you want "holes" you want this: But this is overkill for a racing sim - but this is good for emulating Grass effects using shaders only ( grass on a flat surface without sprites ) If you have played X-Blades - that game demonstrates this effect quite nicely.
Image 3 is a flat surface if your are too lazy to click on links. In because of the note on SL2.0 - means that this 'should' be possible using directX 8