Guide · Glass choice

OEM or aftermarket windscreen glass?

On most cars an OEM-equivalent windscreen is made to the same specification as the genuine part and is the sensible choice. On some cars — particularly with a camera or a heads-up display — we will only fit the genuine one.

The words get used loosely, which is how people end up comparing two quotes that are not for the same thing. This sorts out what the three terms actually mean, what the real differences are, and how to tell which category a quote is talking about.

Newly fitted car windscreen being cleaned from inside the vehicle
Definitions

Three terms, used loosely

Getting these straight is most of the work. Two quotes can differ by a lot and both be honest.

01

Genuine / OEM-branded

Glass supplied through the vehicle manufacturer, carrying their branding, usually made by the same glass company that supplied the production line. The most expensive route, and occasionally the only one available for a recent or unusual model.

02

OEM-equivalent (often just called OEM)

Made by one of the same major glass manufacturers, to the same specification and tooling as the production part, but sold without the car maker’s branding. Optically and dimensionally the same thing. For most cars, this is what we fit and what we recommend.

03

Aftermarket

Made by a third party to fit the vehicle, to a standard rather than to the manufacturer’s exact specification. Quality genuinely varies between brands. Good aftermarket glass is fine on an older car with no sensors; poor aftermarket glass is where the horror stories come from.

The differences

What actually varies, and what does not

Safety standards are not the differentiator — all glass sold for road use in Australia has to meet them. These are.

Genuine OEM-equivalent Aftermarket
Meets Australian safety standards Yes Yes Yes
Made to the maker’s spec and tooling Yes Yes To a standard, not the spec
Optical clarity in the camera window Exact Exact Varies
Frit band, brackets and mouldings Exact Exact Usually close, sometimes not
Acoustic interlayer if fitted originally Yes Yes Often omitted
Fit and wind noise Reference Same Occasionally an issue
Cost Highest Middle Lowest
When it matters

Where we insist on the genuine part

Four situations where the cheaper glass is a false economy and we will say so.

A forward-facing ADAS camera

The camera looks through a specified optical window. Distortion or a slightly wrong wedge angle there changes what the camera thinks it is seeing, and no amount of calibration corrects for bad glass. This is the single most common reason we quote the genuine part.

A heads-up display

HUD windscreens have a special interlayer that stops the projected image ghosting into a double. Fit a non-HUD screen to a HUD car and you get two speedometers, one slightly above the other, permanently.

Acoustic laminate on a quiet car

If the vehicle came with an acoustic interlayer and the replacement does not have one, the car is measurably louder at highway speed. People notice this within a week and it cannot be fixed afterwards.

Heating elements and complex sensor arrays

Heated windscreens, embedded aerials and multi-sensor brackets are where aftermarket parts most often come close but not close enough. Close is not useful when a bracket has to locate a camera.

There is no such thing as “just glass” any more.

A windscreen is a structural panel, an optical instrument for a safety camera, an acoustic layer and a sensor mount. That is why the part number matters as much as the fitting.

When it does not

When the equivalent or aftermarket part is the right call

Most of the time, and we will not sell you a genuine screen you do not need.

On a car with no camera, no heads-up display and no acoustic requirement — which is a very large number of the vehicles on Queensland roads — an OEM-equivalent screen from one of the major manufacturers is the same glass without the badge premium. We fit them every week and they are indistinguishable in service.

On an older vehicle, or one where the genuine part is no longer made, good aftermarket glass is often the only sensible option and works perfectly well. The same applies to some truck and motorhome screens, where glass is frequently cut to pattern rather than pulled off a shelf.

What we will not do is quote you an equivalent, fit an aftermarket screen, and hope you do not notice — or quote a genuine part on a car that does not need one. Ask which category is in the quote. Anyone worth using will tell you plainly.

Keep reading

Cost What a windscreen costs in Brisbane Glass category is one of seven things that move the number. ADAS Calibration after a replacement Why the optical window in front of a camera has to be exact. Compare Mobile or workshop? The other comparison worth making before you book anyone.
Questions

Still wondering

More on the full FAQ page, or just call 0451 180 046.

What is the difference between OEM and aftermarket windscreens?

OEM-equivalent glass is made by one of the same major manufacturers to the vehicle maker’s specification and tooling, without the car maker’s branding. Aftermarket glass is made by a third party to a general standard rather than the exact specification. Both meet Australian safety requirements; they differ in optical precision, brackets, interlayers and consistency of fit.

Is aftermarket windscreen glass safe?

Any glass sold for road use in Australia has to meet the applicable safety standard, so it is not a safety question in that sense. The practical issues with cheaper aftermarket glass are optical distortion, missing acoustic interlayers, and brackets that locate a camera slightly differently — which matters a great deal on a car with driver assistance systems.

Do I need genuine glass if my car has a camera?

On many vehicles, yes. The camera reads the road through a specified optical window, and a wrong wedge angle or distortion in that area cannot be corrected by calibration. We will tell you when your vehicle is one of those rather than fit an equivalent and hope.

Will my insurer pay for genuine glass?

Often, where the vehicle requires it. Insurers are generally used to the argument for camera-equipped and heads-up display vehicles. Tell us your policy details and we will put the case for the correct part — see insurance claims.

How do I tell which glass a quote is for?

Ask directly: is this genuine, OEM-equivalent, or aftermarket, and who makes it? A quote that is much cheaper than the others is usually a different category rather than a better deal, and knowing which lets you compare properly.

Ask what glass is in the quote

Tell us your make, model and year and we will tell you which category your car needs and why. If the equivalent part is the right call we will say so; if only the genuine one will do, we will say that too.

Written and checked by Warren, owner and fitter at Express Auto Glass, twenty years in automotive glass in South East Queensland. Last reviewed .