None.
Revised Statutes of Nebraska
§ 60-6,286. Muffler or noise-suppressing system; prevention of fumes and smoke; requirements
Every vehicle shall be equipped, maintained, and operated so as to prevent excessive or unusual noise. No person shall drive a motor vehicle on a highway unless such motor vehicle is equipped with a muffler or other effective noise-suppressing system in good working order and in constant operation. It shall be unlawful to use a muffler cutout, bypass, or similar device on any motor vehicle upon a highway.
The engine and power mechanism of every motor vehicle shall be so equipped and adjusted as to prevent the escape of excessive fumes or smoke.
§ 60-6,371. Exhaust or intake muffler; change; increase of noise; prohibited
No person shall modify or change the exhaust muffler, the intake muffler, or any other noise-abatement device of a motor vehicle in a manner such that the noise emitted by the motor vehicle is increased above that emitted by the vehicle as originally manufactured. Procedures used to establish compliance with this section shall be those used to establish compliance of a new motor vehicle with the requirements of sections 60-6,363 to 60-6,374.
Former Military Vehicle
Available for a motor vehicle that was manufactured for use in any country's military forces and is maintained to accurately represent its military design and markings, regardless of the vehicle's size or weight, but is no longer used, or never was used, by a military force. Former military vehicle license plates shall display, in addition to the registration number, the designation former military vehicle.
Historical
Available for vehicles that are at least 30 years old and essentially unaltered from original manufacturer specifications. Vehicles registered as historical cannot be used for general daily transportation and the applicant must own and have registered a regular passenger vehicle that can be used for general daily transportation.
Special Interest
Available for motor vehicles of any age that are being collected, preserved, restored, or maintained by the owner as a leisure pursuit and not used for general transportation. Only a single, rear license plate will be issued for special interest plates.
YOM
Vehicles registered as "Historical" may display YOM plates with DMV approval. Only a single rear plate required.
*One license plate shall be issued, upon request and compliance with this subdivision, for any passenger car which is not manufactured to be equipped with a bracket on the front of the vehicle to display a license plate.