No results are counted for close combat against vehicles. The vehicle simply moves away as it wishes in its next turn, while the troops who mounted the assault are free to move, shoot etc normally. Thus assaults against vehicles are very easy to work out – just make your attacks and work out any damage.
Results
Source: Core Rulebook 3E, p. 90
No combat results are counted for an assault against a vehicle; the vehicle simply moves off next turn while the attacking troops act normally.