(a) “Essential parts” means all integral and body parts of a vehicle of a type required to be registered hereunder, the removal, alteration, or substitution of which would tend to conceal the identity of the vehicle or substantially alter its appearance, model, type, or mode of operation.
(b) “Reconstructed vehicle” means every vehicle of a type required to be registered hereunder materially altered from its original construction by the removal, addition, or substitution of essential parts, new or used.
(c) “Specially constructed vehicle” means every vehicle of a type required to be registered hereunder not originally constructed under a distinctive name, make, model, or type by a generally recognized manufacturer of vehicles and not materially altered from its original construction.