Detailed flow measurements are essential for analysing flow structures found in confined spaces, particularly in various automotive applications. These measurements will be extremely helpful in solving flow dependent complexities. Although considerable progress has been made in computational techniques for investigating such flows, experimental flow measurements are still very difficult to carry out therein. Flows mapped using an array of robust instruments like multi-hole pressure probes can provide significant insight into the flow field of such complex flows. Pressure probes can withstand the harsh environments found in such applications; however being intrusive devices significant interference in flow field can limit their applicability. This paper presents an investigation of three-dimensional interference caused by multi-hole pressure probes in an automotive wheel arch. It involves simulation of flow around a pressure probe inserted at various locations within the wheel/wheel arch gap. Pressure and velocity fields along longitudinal and lateral planes have been mapped and the extent of interference caused by the probe along three orthogonal axes has been presented. A three-dimensional ellipsoid of interference has been defined to assist in recommending optimal placement of probes and minimise the error due to interprobe interaction, thus enhancing the measurement accuracy of transient flow phenomena.