A heterogeneous power system in package (PwrSiP) has emerged as a promising approach for automotive and transportation systems. In this paper, a reconfigurable PwrSiP system on a multilayer low-temperature co-fired ceramics (LTCC) substrate for automotive applications is presented. The proposed PwrSiP system consists of an array of switching units (PSU) using GaN HEMT switches, a read-back network using analog-to-digital converters (ADC), and a communication channel using digital isolators. For verification, a PwrSiP prototype that co-integrates all above-mentioned components into a single LTCC substrate package was implemented. The experimental results verified the concept of the proposed PwrSiP. However, many critical issues remain. These issues need to be solved and are addressed along with the directions for future work.