What is a window sticker?

A window sticker — officially the "Monroney label" — is the printed sheet the factory attaches to the window of every new vehicle. It has been federally required on new cars in the United States since the Monroney Act of 1958, and decades later it remains the single most authoritative summary of how a particular vehicle left the assembly line.

It lays out the standard equipment, the optional equipment and packages the original buyer selected, the EPA fuel-economy ratings, the warranty terms, the percentage of U.S./Canadian parts content, and the full price breakdown — base MSRP, each individual option, the destination charge, and the grand total. That original data is exactly what lets you confirm, years later, how a used vehicle was really configured.

Window sticker vs. build sheet

The two documents describe the same factory configuration in different ways. A window sticker is written for the buyer: plain equipment descriptions, fuel-economy ratings, warranty details, and a price breakdown right down to the destination charge.

A build sheet is the factory's own assembly record — the complete list of option codes a vehicle was built with, without pricing. WindowStickerVin.com returns the window sticker whenever one is on file, and automatically falls back to the build sheet when it isn't, so you always come away with the underlying factory data either way. For a deeper comparison, see our guide on window sticker vs. build sheet.

Why check your window sticker or build sheet?

Whether you're buying a used car, selling one, arranging insurance, or just settling a curiosity, the factory record is the most reliable way to confirm exactly how a vehicle was equipped the day it was built — far more dependable than a listing description or a faded memory.

It lets you verify the trim level, the engine and drivetrain, the option packages, and individual features, and it makes it easy to tell factory-installed equipment apart from anything a dealer or previous owner added afterward. For buyers especially, it's a quick way to make sure a seller's claims actually match how the vehicle left the line.

Checking 3RU before buying a used 2026 GMC Acadia

Exterior & Appearance · 2026 GMC Acadia · 249 views · 4 replies

3RU — Primary exterior color: Thai Red, Mica. This code identifies the vehicle's factory-applied main exterior paint color. Browse RPO codes →

Daniel G. Jun 24, 2026 · Illinois

I am considering a used 2026 GMC Acadia. The seller says it has the equipment associated with 3RU, and the code description is “Primary exterior color: Thai Red, Mica. This code identifies the vehicle's factory-applied main exterior paint color” What physical details should I inspect to make sure the listing is accurate?

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4 replies

Brooke P. Jun 25, 2026

A clear photo of the build label, VIN report, and the relevant component would help. Do not post the full VIN publicly; the last eight characters are normally enough for a parts-counter discussion.

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Chris C. Jun 30, 2026

The wording may be abbreviated because these were originally production codes rather than consumer descriptions. “Primary exterior color: Thai Red, Mica. This code identifies the vehicle's factory-applied main exterior paint color” is a reasonable plain-English reading, but the exact implementation should be verified for the 2026 model.

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Maya T. Jul 1, 2026

If the feature is listed but not working, scan all related modules before assuming it was removed. A stored fault, replacement module, or configuration mismatch can make original equipment appear absent.

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Kyle C. Jul 2, 2026

Thanks. I checked the physical equipment and it appears to match the build record. The model-year warning was the part I was missing.

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