This communication presents a miniaturized gradient-index (GRIN) lens integrated into the radome of an automotive radar sensor at 76-81 GHz, i.e., in the E-band, for azimuth beam shaping. The fully dielectric lens is tightly integrated with a multilayer waveguide (MLW) array antenna, yielding a compact footprint of 0.47 & times; 1.2 lambda. A farfield averaging over simulations with different radome widths suppresses diffraction from radome-guided modes, isolating the contribution of the lens-antenna system in the design phase. Measurements of an eightchannel prototype show that the integrated lens broadens the azimuth half-power beamwidth (HPBW) from 50(degrees) to 120(degrees) (approximate to 140 degrees at -5 dB) while maintaining better than 10 dB return loss and a gain ripple of 4.3-7.9 dB across the band. The proposed approach provides a competitive beamwidth in a smaller form factor, enabling integration in automotive corner radar sensors.