Thought I'd weigh in.
62(1) A passenger car shall be equipped with a front and rear
bumper.
(2) No person shall install or alter a bumper on a passenger car
unless the design of the bumper is equivalent to, and the bumper is
mounted in substantially the same manner as, the bumper installed
by the manufacturer of the passenger car.
RSA 1980 cH-7 s62
Height of bumpers
63(1) No person shall alter a passenger car so that the main
structural component of a bumper is more than 50 centimetres or
less than 40 centimetres above ground level when the passenger car
is unloaded.
(o) "passenger car" means a motor vehicle that has a seating
capacity of 10 or less, but does not include an off-highway
vehicle as defined in the Off-highway Vehicle Act, a truck,
a multi-purpose passenger vehicle, a chassis cab, a moped
or a motor cycle;
(w) "truck" means a vehicle designed primarily for the
transportation of property or equipment, but does not
include a chassis-cab, crawler mounted vehicle, trailer,
machinery or equipment used in the construction or
maintenance of highways or an off-highway vehicle as
defined in the Off-highway Vehicle Act;
In reading the above, it appears there are bumper height restrictions for passenger cars By definition it appears pick-up trucks (designed primarily for transportation of property or equipment IMO) are not passenger cars and seem not to have a bumper height restriction.
But, I may be reading this incorrectly.