Side exit exhaust

It certainly is legal. The AAR and T/A cars would not be legal to drive in this state otherwise. I looked up the vehicle code and it is as follows:

175.75. EXHAUST SYSTEMS.
(a) Condition of Exhaust System - All components
of the exhaust system shall be in safe
operating condition as described in §175.80
(relating to inspection procedure) .
(b) Exhaust System Requirements - A vehicle
specified under this subchapter shall be constructed,
equipped, maintained and operated
to prevent engine exhaust gases from
penetrating and collecting in any part of the
vehicle occupied by the driver or a passenger,
in addition to requirements of this title for an
emission control system and smoke control
for a diesel-powered vehicle.
(1) A vehicle specified under this subchapter
shall be equipped with a muffler or other
effective noise-suppressing system in
good working order and in constant
operation. A muffler or exhaust system
may not be equipped with a cutout,
bypass or similar device and a muffler
may not show evidence of external
repair.
(2) The exhaust system of a vehicle may not
be modified in a manner which will
amplify or increase noise emitted by the
motor of a vehicle above the maximum
level permitted by Chapter 157 (relating
to established sound levels).
(3) Headers and side exhaust are permitted
if the vehicle meets the requirements of
this section.
(4) An exposed exhaust system shall be
equipped with an adequate heat shield
or protective system.
(5) An exhaust system shall extend and
discharge completely to the outside edge
of the vehicle body, including a truck
bed, or as originally designed.
(6) A firefighting vehicle is exempt from
regulations concerning exhaust systems,
mufflers and noise control.