A simple integration design of a single layer, dual-feed circular polarization (CP) microstrip antenna for Global Positioning System (GPS) and Dedicated Short-Range Communication (DSRC) applications is presented. The GPS antenna element is excited by a square patch embedded with a corner-truncated square slot; while the DSRC antenna element is a usual corner-truncated square patch that fits perfectly into the slot with a small gap between them. The experimental results show that when loaded with a superstrate (protective cover) provided, the CP performances of the GPS antenna element are only slightly altered while apparent improvement including radiation pattern and peak gain for the DSRC antenna element is observed. Furthermore, the isolation between both feeding ports is well below –23 dB. Hence, this compact antenna design is suitable for mounting onto any vehicle that requires both GPS and DSRC services.