Highly modified and/or Restored vehicles with uprated, non-period correct engine swaps, or engines from outside the original manufacturer, and/or vehicles with significant body customizations or conversions. Generally, Custom vehicles cannot be easily returned to their original factory specifications.

Vehicles that are partially operable, inoperable, disassembled, or incomplete that require meaningful repairs to return to road worthy condition.

Vehicles with a period-correct engine and body, with multiple removable modifications, or a few significant modifications such as increased displacement, added performance equipment (turbo, supercharger, headers), transmission swaps, bumpers, or body wraps. Modified vehicles can generally be returned to original factory specifications.