QNix CrashCheck (QuaNix) Car Body Accident Paint Tester, Meter, Gauge QNix Crash Check (QuaNix) Paint Thickness Tester was developed for used car trading Easily locate areas of car body with consealed damage or rust With the QuaNix CrashCheck the thickness deviation can be figured out, fast and reliably. Patented New Measurement Device (No other product like it on the market). CrashCheck is an ideal car body damage and accident tester.