A low-profile and compact 3D antenna operating at LTE, GSM and UMTS frequency bands (790–2690 MHz) is proposed for a vehicular 2×2 MIMO system. The performance of the single 3D radiating element is here analyzed. Then, the two-antenna system performance is analyzed in terms of impedance matching, isolation and envelope correlation coefficient, highlighting the effect of some geometrical parameters such as inter-element distance and reciprocal orientation. Preliminary measured results are presented.