Simultaneous Transmit and Receive (STAR) systems typically utilize multiple cancellation layers to improve system isolation and avoid self-interference. The design of these different layers must be evaluated both individually and as a whole to determine their effectiveness in various environments. A flexible and reusable mobile testbed was constructed to aid in the development and assessment of these different STAR technologies for both stationary and non-stationary applications. The usefulness of this platform was confirmed during the integration of an example STAR system that measured greater than 100 dB of total system isolation over a 30 MHz bandwidth centered at 2.45 GHz.