M化車被媒體讚譽為破案神器。偵查人員使用M化車之目的，一是透過手機IMEI，來截收SIM卡的IMSI，藉以向電信業者調取通訊使用者資料，另一是對目標手機所在位置實施追蹤定位。在德國也有相同功能的偵查方法，稱作IMSI-Catcher，至於它被裝載在什麼交通工具，稱為M化車或M化無人機均無關宏旨。IMSI-Catcher是否干預目標手機持有人的個人基本權利？答案如為肯定，我國法有無提供追訴機關干預授權基礎？這兩個前後牽引的問題意識，是本文寫作出發點。本文研究結論認為，IMSI-Catcher截收手機的IMSI與IMEI和追蹤定位，會干預個人資訊自主決定權。然而，於我國刑事訴訟法、通訊保障及監察法以及警察職權行使法，均欠缺IMSI-Catcher干預授權基礎，亦即，現行M化車偵查實務不具備合法性。面對我國實務需求和立法缺口，2002年已將IMSI-Catcher偵查法制化的德國刑事訴訟法第100i條，並經德國聯邦憲法法院合憲性審查，應可作為比較法先例之借鏡。鑑於IMSI-Catcher的偵查實務重要性和對個人基本權利干預的觀察，期盼本文之研究能為M化車偵查帶來些許省思和比較法啟示。

The M-Car is praised by the media as a magic weapon for solving crimes. The purpose of investigators using the M-Car is to intercept the IMSI of the SIM card through the IMEI of the mobile phone, so as to retrieve the communication user information from the telecom operators, and the other is to track and locate the location of the target mobile phone. In Germany, there is also a investigation method with the same function, called IMSI-Catcher. As for what kind of vehicle it is loaded on, it does not matter what it is called a M-Car or a M-UAV. Does IMSI-Catcher interfere with the basic human rights of the target mobile phone holder? If the answer is yes, does the law provide a basis for prosecution agencies to intervene in authorization? These two traction problems are the starting point for writing this article. The conclusion of this article is that IMSI-Catcher’s interception of IMSI and IMEI and tracking and positioning of mobile phones will interfere with the personal right to informational self-determination. However, the Code of Criminal Procedure, Communication Security and Surveillance Act, and Police Power Exercise Act all lack the basis for IMSI-Catcher intervention authorization, that is, the current M-Car investigation practice does not have legitimacy. Facing the practical needs and legislative gaps, Article 100i of the German Criminal Procedure Law (Strafprozessordnung), which has legalized IMSI-Catcher investigation in 2002, and has been reviewed by the German Federal Constitutional Court (BVerfG) for constitutionality, should serve as a reference for comparative law. In view of the importance of IMSI-Catcher’s investigation practice and the observation of the intervention of basic rights of individuals, it is hoped that the research in this article will bring some reflections and comparative enlightenment to the investigation of M-Car.