Used car buyers and dealers cannot easily see price fluctuations over time for specific vehicles on carsensor.net. This extension overlays historical price trend charts onto car listings, helping users assess whether a car's current price is fair based on historical data.

1. User installs extension and browses carsensor.net normally. 2. On search result pages, the extension injects price history line chart images (from nedukekun.com) for each listed car. 3. On individual car detail pages, the extension adds interactive charts showing price trends, grade distribution, and market analysis using Chart.js. 4. The extension also displays banner ads promoting the related paid product 'くるま値付けくん'. 5. No login or account setup is required to see the charts.

Target users: Used car dealers and salespeople browsing carsensor.net / Individual used car buyers researching fair market prices on carsensor.net / Japanese market participants interested in vehicle price trend analysis

The extension heavily depends on external services (nedukekun.com for chart images, carsensor-vision.appspot.com for API data, store-can.appspot.com for ads) whose server-side behavior could not be fully inspected
The ucarChart.js file (1125 lines) was only partially read; it contains the interactive chart rendering logic but may have additional features not captured
Some features referenced in sworker.js (auth, fetchBukken, updateMemo, updatePurchasePrice) appear designed for the related paid product 'くるま値付けくん' but their full integration path could not be traced

Monetization

No paid features detected

The extension itself is free and does not gate any features behind payment. It displays price history charts and ads on carsensor.net for all users. The store description explicitly states '有料版のくるま値付けくんの製品紹介動画が検索結果に表示されます' — this confirms the extension promotes a SEPARATE paid product called 'くるま値付けくん' (via banners linking to nedukekun-lp.com and embedded iframes from store-can.appspot.com), but does not itself have paid features. The hardcoded token in config.js is an API authentication token for the backend service, not a user payment token. No subscription, billing, upgrade, or payment UI exists in the extension.

Confidence: 85
Payment platform: --
Source: AI / Medium
Login required: No
Reason: The extension's core workflow — displaying used car price history charts on carsensor.net — works without any login. Images are loaded from nedukekun.com using only the car ID (carsensorId) and a locally-generated anonymous UID. While sworker.js contains an auth function (line 765) that accepts shopId/kokyakuCd and calls an API auth endpoint, this is only triggered when a 'auth' message is sent from content scripts. The main.js content script never sends this auth message; it only calls getConfig and getAd. The auth/shopId features appear to be vestigial code from the related paid product 'くるま値付けくん' rather than required for this extension's free functionality.

Permission risk

Low-risk permissions

This estimate uses declared permissions and host permissions to assess access scope and sensitivity.

未命中敏感权限或广域站点访问规则

Publisher

dev.app5jp

Independent publisher

Email: [email protected]
Phone: --
Address: 別所温泉１９５−１上田市, 長野県 386-1431 日本

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中古車の価格変動が丸わかり - 中古車チェッカー

中古車の価格変動が丸わかり - 中古車チェッカー Media preview

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