Consider Case Theory (you using the S / D Structure distinction), given VP internal subject hypothesis.
VP[DP[He] V'[V[drive] DP[a car]]]
Case theory mandates that the Subject be assigned Nominative, and the Object Accusative. Thus, Operation Move comes into play:
AgrS P[Spec[t DP[He]] VP[
V'[V[drive] DP[a car]]]
(omitting TP operation):
AgrS P[Spec[t DP[He]] TP[Spec[3rd sing, present] T'[T[t2 drives] AgrO P [Spec [sing] AgrO' [AgrO[DP[t3 a car]] VP[t1 V'[t2 t3]]]]]
Therefore, due to the syntactic requirements that the lexicon imposes (DP singularity, Case, VP Tenses, etc.), everything originally in the VP is moved out of it, leaving only traces behind. Thus DS is altered as syntactic complexity increases.
Hope this helps.