I know it does not reflect sortie information, but the M3 still had 1466 deaths in October vs 4552 deaths in September. If you consider that the M3 could potentially "land" in town, 1466 is a lot of usage for a vehicle that just delivers supplies.
The German halftrack went from 276 to 2562 deaths from September to October. Comparing the increase in sorties of the German halftrack to the M3 decline, the difference is about 1990, very close to the deaths the M3 had in October (again, the difference could be affected by landing out in town).