This paper aims at studying and evaluating the impact of Evil Waveform (EWF) distortions, stemmed from the aeronautical domain and the extension of detection strategies to automotive sector applications. The EWF event can be described as the transmission of a faulty PRN from a given GNSS satellite, being characterized/modelled by a combination of digital and analog distortions, which translates into different effects of the affected PRN. The associated distortions imply specific Signal Quality Monitoring (SQM) mechanisms able to detect them. These techniques are described, clarifying its definition and proposing a new SQM solution from the joint processing of three types of tests in order to provide the desired robustness necessary for the detection of such events.