Well, first of all, I'm not simply referring to the "downpipe"
but, rather to the full length, straight through, exhaust pipe,
sans muffler.
I believe several people, on this forum, which originates
in CANADA, have already done this modification.
However, I am unsure whether they did so for STREET or TRACK,
and whether they know the ramifications of this mod for a street
use daily driver as I recently bought a parts car with this
modification already performed.
Finally, while it's certainly true, I CAN look into this myself, always
assuming I can get hold of an actual person at the DMV, it's also
true that those people seeking parts numbers, or other miscellaneous
information, could always ask at the dealership.
Surely, fora, such as this, exist as a source of fairly quick, reliable
information, for interested parties, from those who have both the
knowledge and the prior experience which, with respect to your
response, does not appear to be the case.
Indeed, as I pointed out, my concern is within CANADA, and, more
specifically, in the Province of Ontario, where many of the participants
on this forum reside.
Since you are from Utah, Yew Ess Ay, where the laws governing
such modifications are unlikely to be identical to those in Ontario,
CANADA, I'm somewhat puzzled as to why you would take the
trouble to respond to a question to which you, clearly do not have
the answer.
However, I do thank you for your...er...interest.