How does the AI "Car Wash Test" link back to QE?
24 Sep 2026
If you ask an AI model, "I need to get my car cleaned, and the car wash is 100 metres away, should I walk or drive?", several popular LLMs tell you to walk. They give you a well-written breakdown on saving petrol, squeezing in a quick bit of exercise, and avoiding the hassle of starting an engine for a short trip.
It sounds sensible, until you remember the physical reality: walking 100 metres leaves your dirty car sitting in the driveway.
The model isn't reasoning. It catches keywords like "100 metres", "walk", and "drive", and immediately routes down a path of health and environmental advice. It completely misses the actual goal because it lacks a basic mental model of how the physical world fits together.
We see this exact pattern play out in Engineering when teams blindly rely on AI.
Generative tools are great at drafting options, but as Quality Engineers, we have to supply the common sense.
~ Look past the surface logic: An AI response can sound articulate and convincing while missing a fundamental physical or business constraint.
~ Validate against the real-world goal: Always ask if a test scenario actually gets the "car to the car wash," or if it's just ticking a box on a screen.
As a Lead Test Engineer, with 15 years experience, Deborah specialises in quality engineering, risk management, and scaling test strategies.
Over the years, she has spearheaded quality operations for major international expansions, including multi-region deployments and scaled QE to support expanding product domains. Most recently, she's focused on driving shift-left quality practices and automation.
She is deeply passionate about fostering a quality-first culture that balances speed with stability. Her approach centres on pragmatic automation - leveraging tools like Cypress where they add maximum ROI, paired with targeted exploratory testing to safeguard complex user journeys.
She also has a passion for accessibility testing and has written a course on the topic https://www.ministryoftesting.com/courses/introduction-to-accessibility-testing?s_id=19046932
