What Makes a Car Street Legal? [12 elements to consider]

What Makes A Car Street Legal? [12 elements to consider]To an enthusiast, cars serve more than just a practical purpose. We are intrigued by concept cars, excited by streamlined racers or rugged off-roaders, and tempted by the latest performance-enhancing modifications. But, when it comes to driving any vehicle down the road, what does it mean to be street legal? We have looked into this subject so you can have all the answers that you need!

Driving a street-legal car means that your vehicle has all the equipment or features required by law to operate the vehicle on public roads. Typically, street-legal laws ensure that all vehicles are equipped with safety equipment and emission control systems. Street legal laws do vary from state to state so, check with your local Department of Motor Vehicles (DMV) to learn the requirements for your state before driving your car on the road.

Let's take a look at some of the most widely accepted street legal requirements statewide.

What Are the General Requirements for a Street Legal Car?

States mandate street legal requirements to keep drivers safe on the roadways. While street-legal laws do vary by state, there are some general safety features, emission control systems, and registration requirements that all cars must have to be considered street legal in all states.

Although several of your car’s features seem necessary to operate the car, most of these features are also required for the car to be considered street legal such as:


Your car’s tires must be installed in a way to prevent debris from flying up toward other vehicles. Having fenders or mud flaps on your car usually covers this requirement. Tires must also be in safe working condition so, many states require a minimum of 2/32 inch tread on tires.


It seems obvious that your car must be equipped with brakes, but most state “street legal” laws also mandate that your vehicle has a functioning parking brake.

Steering Wheel

Rotated car steering wheel

How could you maneuver without a steering wheel? That fact is that your vehicle must be equipped with a circular steering wheel of at least 13 inches diameter to be considered “street legal.”

Engine Hood

Not only does the hood on your car protect the engine components but, an engine hood is required by law to be considered “street legal.” In most states, modifications to the hood are also regulated. For example, air intakes and hood scoops cannot be more than 4 inches above the hood’s surface.


Your car’s windshield is mandatory, and most states do not allow any tinting of the windshield.

Windshield Wipers

Windshield wipers are vital during inclement, snowy, or rainy weather to help you see clearly while driving. It is illegal to drive a car without windshield wipers.

Lights & Reflectors

Of course, without lights, it would be impossible to drive your car at night. Lights also alert you and other drivers of oncoming traffic. Reflectors keep your car safe when it is parked, by coming aglow as moving cars pass to alert drivers of your parked car’s location. Your car must be equipped with lights and reflectors that comply with the Department of Transportation (DOT) federal regulations:

  • Headlights (White)
  • Taillights (Amber)
  • Turn Signals (Amber)
  • Stop Lights (Red)
  • License Plate Light (White)
  • Hazard Warning Signals Front/Rear (Amber/Red)
  • Backup Lights (White)
  • Side Reflectors (Amber)
  • Rear Reflectors (Red)


Your car must be equipped with at least two rear-vision mirrors to be considered “street legal” in most states. The exterior driver’s side mirror and the interior rear-view mirror meet this requirement. For larger vehicles, like an RV or a box truck where the rear-view mirror’s view might be blocked, a second exterior mirror on the passenger-side meets the “street-legal” requirement.

Seat Belts

Woman putting seat belts on for safety

In 1968, the federal government mandated that all new cars be equipped with seat belts. Not only are seat belts mandatory equipment for a “street legal” car, but, except for New Hampshire, all states also require seat belts to be worn by an adult, front-seat passengers. In as many as 30 states, seat belts are required to be worn by adult, rear-seat passengers. State regulation of seat belt laws does vary by state but, it’s best always to buckle up before you move your car.


Your car’s horn is a useful warning signal and a necessary piece of safety equipment for your vehicle to be considered “street legal.” The sound of the horn should be audible within at least 200 feet.

Mufflers & Exhaust Control Systems

To control pollution, the federal government mandates that all “street legal” cars be equipped with a muffler and exhaust control system. Exhaust system components should be securely mounted to the vehicle at the rear of all doors and windows but within 15 inches forward of the rearmost part of the vehicle. Exhaust systems should not be temporarily patched or repaired as a temporary fix could result in leaking.

State enforcement of exhaust control varies by state, so check with your local Department of Motor Vehicles (DMV) for your state’s emissions requirements. Currently, 33 states do require an exhaust/emissions check as part of annual car inspections.

License Plate

Every state requires your car to display an unobstructed, lighted license plate mounted on the rear of the vehicle. Many states also require a front-mounted license plate. Your local Department of Motor Vehicles (DMV) is a great source to determine where to mount the license plate(s) on your car.

What Makes a Car Street Legal in Florida?

The state of Florida has a few variations on general “street legal” requirements for your car:

  • Two braking systems are required, in addition to a functional parking brake. Each braking system must be able to stop your car within the braking distance, as illustrated on this chart provided by the State of Florida Department of Motor Vehicles.
  • Front and rear bumpers are required on cars and pickup trucks. Bumpers should be mounted within certain height levels as determined by the new (not modified) shipping weight of the vehicle.
  • Side windows cannot be composed of, covered, or treated with any highly reflective or mirrored material that reflects more than 35% of light.
  • Rear windows cannot be composed of, covered, or treated with any material to make the window non-transparent.
  • It is illegal to tamper with, remove, or damage your car’s exhaust control system.

Most other general “street legal” requirements do apply in Florida. Check the State of Florida DMV website for additional information.

What Makes a Car Street Legal in California?

The state of California has a few variations on general “street legal” regulations for your car:

  • Smog inspections (valid 90-days) are required for all vehicles to be registered as “street legal” with the expectation of diesel-powered cars from 1997 or older or with Gross Vehicle Weight (GVWR) of more than 14,000-lbs., electric cars, natural gas-powered cars weighing over 14,000-lbs., and gasoline-powered cars from 1975 or older.
  • Noise from a muffler and exhaust control system must not exceed 95 decibels.
  • Windshield tinting allows a transparent strip only on the top 4 to 5 inches of the windshield. No color-altering is permitted for tinting.
  • Front window tinting must enable more than 70% of light to pass through. No color-altering is permitted.
  • Rear window tinting has no requirements for the percentage of light to pass through. No color-altering is permitted.
  • Underglow lights are legal although, some restrictions apply to the size, positioning, and color of underglow lights.

Check the State of California DMV website for additional information about “street legal” registration requirements.

What Typical Modifications Make a Car Not Street Legal?

If you are a car enthusiast, you know that driving is not the only thrill you seek. Car enthusiasts often enjoy tinkering, modifying, and remodeling cars. You might want higher ground clearance, a flashy exterior, or louder performance. But do some of these modifications make your car no longer “street legal”? Let’s take a look at some common, illegal car modifications.

Ground Clearance

Lifting or lowering the height of your car might be illegal, depending on how low or high you go, because it alters the car’s handling and performance. Check your state’s height restrictions before you modify your car. Typically, states do not allow lifts of higher than 4 inches.

Neon Lights

A bright underglow from neon lights can be distracting to other drivers. Before you add flashy flair to your car’s undercarriage, check with your state’s regulations for neon light size, positioning, and color restrictions.

LED Headlights

Car blinding LED Headlights

Brighter is not always better. Some LED lights can be blinding to oncoming drivers. Check your state’s headlight laws before modifying any light bulbs in your car. Generally, states do specify various types of approved light bulbs, light covers, and how to position headlights to prevent glare legally.

License Plate Frames

It is not illegal to add a bit of bling to your license plate. Just make sure your license plate frame does not obscure the ability to read the license’s state of origin or any of the numbers or letters depicted on the plate.

Muffler/Exhaust Noise

Being heard might not only get you noticed, but it might also get you a ticket. In most states, it is illegal to tamper with your car’s exhaust system due to pollution control. However, the exhaust control system also mitigates noise, and many states mandate your car’s exhaust should not produce more than 90 decibels of volume. Check before you modify because Texas, for example, has no “street legal” noise regulations.

Studded Tires

Winter drivers are all too familiar with studded tires, to give extra grip in the snow. But, some car enthusiasts like the cosmetic look of studded tires. Whether you add studs for the function or the curbside appeal, studded tires are illegal in most states during warm weather months. Studded tires can easily skid on dry surfaces, posing a risk to you and other drivers on the roadways.

Get the facts before you get into your car for a drive or make modifications. If some of these street legal laws seemed surprising to you, check with your local Department of Motor Vehicles to learn the street-legal regulations for your state.

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