I'd say so! The spell states "This spell may be cast on a single enemy unit (which may be in combat) within 24" and line of sight. Any of the unit's To Hit, To Wound, armour save or ward save rolls of 6 are counted as being 1s until the beginning of the next friendly magic phase."
Impact hits top left of pg63 "When a chariot charges a unit, it causes D6 hits with its own Strength" which sounds like a To Hit roll to me. Impact hits resolved to find how many hits actually strike your unit (or theirs, if the chariot is fleeing through enemy troops) which I'd say would be affected by the spell along with the rolls To Wound too.