The under-hood automotive ambient is harsh and its impact on electronics used in electronic control unit (ECU) assembly is a concern. The introduction of Euro 6 standard (Latest European Union Legislation) leading to increase in power density of power electronics in ECU has even amplified the device thermal challenge. Heat generated within the unit coupled with ambient temperature makes the system reliability susceptible to thermal degradation which may result in catastrophic failure if not efficiently dissipated. Previous investigations show that the technology of thermal interface materials (TIMs) is a key to achieving good heat conductions within a package and from a package to heat sinking device. With studies suggesting that conventional TIMs contribute about 60% interfacial thermal resistance, innovative technology is required to improve the thermal performance of TIMs. A review of emerging nanotechnology in TIMs shows that carbon nanotubes (CNTs) and carbon nanofibres (CNFs) when used as the structure of TIM or TIM filler could improve the overall thermal and mechanical properties of TIMs. Hence, CNTs/CNFs have the potentials to advance thermal management issues in ECU. This search identifies chemical vapour deposition (CVD) as a low cost process for the commercial production of CNTs. In addition, this review further highlights the capability of CVD to grow nanotubes directly on a desired substrate. Other low temperature techniques of growing CNT on sensitive substrates are also presented in this paper.