25 May, 2023

Did Aftermarket Modifications Cause Your Accident?

Author Todd A. Strong
night car ride by car equipped with Head-up display

There are two areas to consider when discussing aftermarket parts. The first is when only the component itself is replaced. This applies to repairs on a vehicle. Repairs are often subsidized by insurance companies, if a vehicle was damaged enough to warrant an insurance claim. The companies want to save costs, or the owner is paying out of his or her pocket and wants to save time and costs. Aftermarket parts are usually used in favor of OEM parts in standard repairs.

night car ride by car equipped with Head-up display

While legal, aftermarket modifications are usually less safe than a factory car, and each modification increases the potential of an accident. The aftermarket car part industry manufactures, remanufactures, distributes, sells, or installs parts, equipment, accessories, or alterations of the vehicle after the original manufacturer has sold it. Some of these modifications function as intended. Others, however, affect the vehicle’s operation and performance. 

If you have been in an accident, and aftermarket modifications caused your accident, you may be entitled to compensation.

What Are Aftermarket Car Parts?

Aftermarket car parts are parts used to replace damaged or broken parts when repairing a vehicle. If you take your vehicle to be repaired at the dealership, they will use Original Equipment Manufacturer (OEM) parts to replace any damaged or broken parts. If you take your vehicle to an independent repair shop, they are more likely to use aftermarket parts. These are replacement parts that are designed to function the same as the OEM parts, although they are manufactured by someone other than the original manufacturer.

Statistics Regarding Aftermarket Modifications

On average, OEM parts cost 60% more than comparable aftermarket parts. Despite saving money on repair costs, Men’s Gear LTD reports drivers of aftermarket modified vehicles face a 27% increased chance of getting into an accident as compared to drivers of vehicles with OEM parts.

Reasons for and Against Using Aftermarket Parts

Aftermarket parts are usually used because they are cheaper but able to carry out the function of the OEM parts. They are not always of bad quality, and sometimes it makes sense to use aftermarket parts. 

However, with benefits, there are often risks:

  • Repairs are cheaper. OEM parts are more expensive, so with aftermarket parts, you will pay less and can shop around at various stores for the best price. You may be able to save a significant amount of money. However, you must be cautious, as with cheaper parts, the quality is often lower. To get a lower price, manufacturers may use lower-quality materials or skip quality control.
  • They are more easily available. With OEM parts, you must order from the dealership or the dealership’s website directly. This means that if the dealership does not happen to have stock, you may have to wait weeks or more for the dealership to order and get the part in. Aftermarket parts tend to be more readily available and are typically stocked at a local auto parts store and online. This means they are easier to obtain, and there is a large selection to choose from. With this selection, you are more at risk of selecting the wrong part, or one not specified for your vehicle. This risks a faulty repair.
  • Quicker repairs. Because aftermarket parts are more easily available, you are able to get the repair done quicker and get back on the road sooner. However, since they are generic, they may not fit your car properly, wear faster, be designed differently to the manufacturer’s intentions, or be of lower quality materials. So, while the repair is quicker, it may devalue your car or be unsafe.

There are two areas to consider when discussing aftermarket parts. The first is when only the component itself is replaced. This applies to repairs on a vehicle. Repairs are often subsidized by insurance companies, if a vehicle was damaged enough to warrant an insurance claim. The companies want to save costs, or the owner is paying out of his or her pocket and wants to save time and costs. Aftermarket parts are usually used in favor of OEM parts in standard repairs.

The second is when aftermarket modifications are performed on a vehicle using aftermarket parts. This is where the vehicle is changed from its original configuration. This includes ambulances, limousines, mobility vehicles, or off-road vehicles. Aside from functionality modifications, these can also be aesthetic or performance enhancing, such as flashy rims, hydraulics, or engine enhancers.

Common Aftermarket Parts

There are any number of aftermarket parts, as well as car modifications, that a car owner might make to his or her car. Some are mundane and will not significantly affect safety, such as a tow-bar, alarm, or parking sensors. Some repair vehicle damage, such as engine parts, doors, and bumpers. Other parts can be inherently dangerous, such as lights that can influence other drivers’ visibility or performance systems that give a car more power. 

Some common aftermarket parts and modifications are:

Cold Air Intakes

Cold air intakes are supposed to boost an engine’s performance, improve fuel consumption, and have reusable filters. However, cold air intakes collect more dust and clog easily. This can cause a failed emissions test and cause the mass airflow sensor to fail.

Performance Exhaust Systems and Mufflers

These are supposed to allow more airflow, which in turn generates more horsepower, as well as gives the engine a louder and throatier sound. However, this can create problems with the oxygen sensors and catalytic converters, which makes the car more dangerous to drive. The loud noise can also startle other drivers, pedestrians, or cyclists, which creates its own danger as they might act unpredictably.

Superchargers or Turbochargers

These increase the power of a vehicle. However, the engine parts of a vehicle may not be designed to handle the extra strain. Turbochargers cause a more violent explosion within the engine, which puts a greater strain on the valves. Superchargers use air to increase power, so if they are overcharged they will blow hot air into the engine, causing damage. They also expose the engine to higher pressures, putting additional strain on engine components.

Improper installation or defects in these units can cause damage to an engine, making it unsafe while driving.

Wheels, Suspensions, and Tires

Suspension systems in a vehicle are complex, involving different parts. Putting on non-standard wheels or tires can create problems with the suspension, wheel bearings, and breaks. Putting aftermarket parts in the suspension can damage the suspension system easily, affect car handling, or cause the safety features of the vehicle to be unable to work properly. Changing wheels, suspensions, or tires could cause the vehicle to behave abnormally while driving, leading to dangerous driving situations.

Who Is Liable If Aftermarket Modifications Cause a Car Accident?

If you have been in an accident caused by aftermarket car parts, you can bring a personal injury lawsuit to recover damages. Generally, a person who caused an accident, by manufacturing or installing a faulty or incorrect part, or a driver who installs an unsafe modification, leading to an accident, will be liable for damages resulting from the accident. Every case is different, although there are certain parties that are commonly held liable.

Insurance Company

Usually, in a car accident, the at-fault driver will have third-party insurance coverage, meaning that the insurance will pay out if the covered driver is at fault. Any other party who suffered damages will make a third-party insurance claim with the at-fault person’s insurance company. If an accident was caused because of another driver’s defective aftermarket parts or modifications, then his or her insurance company becomes liable.

Sometimes, when an insurance company pays for repairs, it will require aftermarket parts to be used to save costs. There have been lawsuits against insurance companies requiring aftermarket parts to be used, where such parts turned out to be inferior.

Vehicle Owner

If the owner of the aftermarket vehicle has made modifications that have caused an accident, he or she will be liable. If the owner was insured, he or she may still be liable if he or she did not inform the insurance company of the modifications.

The aftermarket modifications may lead to an accident where the driver is uninsured or underinsured. The difference between uninsured and underinsured is that uninsured means a person has no insurance coverage at all, while underinsured is where someone has insurance, but the policy limits are insufficient to pay for the full claim. In such a situation, the owner would be liable for the difference between the insurance coverage and the full amount of the claim.


The average driver does not have sufficient knowledge of a vehicle’s mechanics, nor details of the repairs getting carried out, to ensure that the parts used are safe. If a mechanic knowingly uses inferior or incorrect parts or does not correctly install a part, causing it to fail, then the mechanic will become liable if aftermarket modifications cause an accident.


Sometimes parts may be low quality when manufactured, either because of a bad design or using inferior materials. If this is the case, the part can fail even if installed correctly. If a manufacturer has provided a substandard part, and it can be proved that this caused the part to fail resulting in an accident, then the manufacturer can be held liable.

A car accident lawyer can help you identify the at-fault party in your case and hold them liable for injuries caused by aftermarket modifications.

About The Author

Photo of Todd A. Strong
Illinois workers’ compensation and personal injury lawyer Todd A. Strong is the founder of Strong Law Offices in Peoria, Illinois. Todd brings considerable legal knowledge, experience, and skill to the table to ensure injured victims throughout the state are treated with respect, dignity, and fairness.