
Ford Sierra Sapphire 4-door Polycarbonate Windows
Create your ideal windows below, or contact the team if you have a specific requirement.
Customise your windows:
Note: Unless stated, all windows are sized to fit into rubber seals. If you need bolt-in sizing, then please contact us.
Shipping calculated at checkout.
US orders ship in 3 weeks (5 for hard-coated). Delivery in 3–17 business days, depending on location.
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Product information
Every Race Plastics window is custom-made by our experienced team in the UK. Built for motorsport, these polycarbonate windows are lightweight, shatterproof, and far stronger than glass. Unlike acrylics or Perspex, they won’t crack under pressure—giving you peace of mind when you’re pushing hard.
Our standard spec uses 4mm thick polycarbonate, meeting key racing regulations. If you need more strength, we also offer 5mm FIA-compliant windows and hard-coated options for extra durability and scratch resistance.
Windows come in clear, bronze, or grey tints, so you can match the look to your build. You can also add sliders to either or both front doors, depending on how you want to manage airflow.
Window Sliders
Our slider kits are built from the same high-quality polycarbonate as your main windows. Designed for both driver and passenger sides, they’re smooth, secure, and built to last.
You can choose between:
- Smooth operation with three fixed positions, no rattle
- Simple and reliable, with two preset stops
Easy to fit and made to avoid rubbing or scratches, these sliders are ideal whether you need more air on track or better control on the road. For full specs, visit the Window Slider Kits page.
How long does shipping take?
We’ll confirm your order right away. Standard polycarbonate kits are usually built and shipped within 3 weeks. Custom or hard-coated orders may take longer—we’ll reach out to confirm the lead time. If you’ve got a race coming up, let us know and we’ll do what we can to hit your timeline.
Can I install the windows myself?
Yes. Most builds are straightforward and there are plenty of how-to videos online. Unless stated otherwise, our windows are made to fit into standard rubber seals. Need bolt-in versions? Just reach out.
Can I pick up my order?
We usually ship via courier, but yes—collection from our Leeds facility can be arranged. Just drop us a message.
Need to change your order?
Get in touch as soon as you can. We’ll do our best to make changes, but if production’s already started, there may be a cost to amend the order.
Key product info:
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Expertly crafted in the UK
All of our windows and sliders are hand made to order by our team in the UK.
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Motorsport compliant
Our standard windows are made from UK compliant 4mm Polycarbonate.
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FIA & hard-coated options
We also offer FIA compliant 5mm & hard-coated options.
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Road legal warning
Always check your local vehicle regulations before fitting.
Not found what you need?
Need a single window, or have a special requirement, no problem. Just let us know what you need.
The Ford Sierra Sapphire 4-door rally car
At first glance, the Ford Sierra Sapphire looked like just another family saloon, a practical four-door version of Ford’s well-established Sierra hatchback. But beneath its sensible, business-like exterior lay the DNA of a true performance legend. Introduced in 1987, the Sierra Sapphire retained the key elements of the original Sierra while refining its aerodynamics, handling, and, in certain versions, unleashing some of the most exhilarating performance ever found in a four-door saloon.
The Sierra had already made a name for itself in motorsport, with the three-door Sierra RS Cosworth tearing up touring car championships and proving itself as a rally weapon. However, Ford knew that not everyone wanted a big-winged, three-door homologation special, some people wanted power with a touch of subtlety. Enter the Sierra Sapphire RS Cosworth, a four-door version of the Cossie that brought all the speed and aggression of the original but wrapped it in a more understated, everyday-friendly package.
Under the bonnet was the same 2.0L turbocharged Cosworth YBB engine, producing 204 horsepower in early models, with power jumping to 220 horsepower in the later 4x4 version. In a car weighing around 1,250 kg, that meant serious performance. The rear-wheel-drive models were tail-happy monsters, with plenty of power sent to the back wheels, making them an absolute joy for skilled drivers, or a terrifying handful for the unprepared. The later Sierra Sapphire RS Cosworth 4x4, introduced in 1990, added a permanent all-wheel-drive system, improving grip and making it even more of a threat on wet or loose surfaces.
The Sapphire Cosworth wasn’t just a road-going rocket, it was a motorsport powerhouse. Ford built a Group A racing version, which saw action in touring car championships and rallying. In the hands of teams like Texaco Eggenberger and Andy Rouse Racing, the Sierra Sapphire dominated circuits across Europe, Australia, and beyond, battling the likes of BMW M3s and Nissan Skylines in some of the most legendary tin-top races of the late 80s and early 90s.
In rallying, the Sierra RS Cosworth 4x4 became an essential stepping stone for Ford’s transition into the Escort Cosworth era. While it didn’t reach the dominance of some AWD rally cars of the time, its balance, turbocharged power, and rugged drivability made it a popular choice in national and privateer rally teams, proving its capability on gravel, tarmac, and snow.
Even beyond the RS Cosworth models, the standard Sierra Sapphire was a brilliant car in its own right. It was comfortable, practical, and well-built, offering a smooth ride and decent performance in its more common 1.8L and 2.0L variants. Whether being used as a company car, family hauler, or weekend racer, it became one of the most popular saloons of its era, earning its place on Britain’s roads in huge numbers.
Today, the Sierra Sapphire, especially the RS Cosworth versions, is an absolute legend. It’s become a sought-after classic, with values skyrocketing as enthusiasts and collectors hunt for original, unmolested examples. The combination of four-door practicality, rear-wheel-drive madness, and turbocharged power makes it one of the most exciting performance saloons ever built, a car that could blend into traffic one minute and leave sports cars in its dust the next.
For those who drove one, the Sapphire Cosworth wasn’t just a car, it was an event. The turbo lag, the boost surge, the feeling of an old-school Ford trying to shake itself loose at the rear, it was a thrill every time you got behind the wheel. Whether in racing livery, rally trim, or a well-kept street sleeper, the Sierra Sapphire remains one of Ford’s greatest achievements, a reminder of a time when family cars could also be absolute monsters.

Thought about a slider kit?
Our easy retro fit window slider kits are the essential addition to your racing windows with standard and advanced kits available.
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Let customers speak for us
from 7 reviewsVery helpfull
Nicely finished, very well packed, arrived on time and great value. Thanks!
Windows are easy to fit and look good
Would highly recommend Race plastics. I have used them now on 3 occasions, their products and their customer service are the best I have used, Thank you R.P....
Perfekt fitting, fast delivery.
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