Like most laws there are gray areas and it depends how you interpret them.The feds also seem to defer you to state law.
b)(1) Subsection (a) of this section does not apply to a removal,
obliteration, tampering, or alteration by a person specified in
paragraph (2) of this subsection (unless such person knows that the
vehicle or part involved is stolen).
(2) The persons referred to in paragraph (1) of this subsection
are--
(A) a motor vehicle scrap processor or a motor vehicle
demolisher who complies with applicable State law with respect to
such vehicle or part;
(B) a person who repairs such vehicle or part, if the removal,
obliteration, tampering, or alteration is reasonably necessary for
the repair;
(C) a person who restores or replaces an identification number
for such vehicle or part in accordance with applicable State law;
and
(D) a person who removes, obliterates, tampers with, or alters a
decal or device affixed to a motor vehicle pursuant to the Motor
Vehicle Theft Prevention Act, if that person is the owner of the
motor vehicle, or is authorized to remove, obliterate, tamper with
or alter the decal or device by--
(i) the owner or his authorized agent;
(ii) applicable State or local law; or
(iii) regulations promulgated by the Attorney General to
implement the Motor Vehicle Theft Prevention Act.
