Meet the weBoost Drive 4G-X OTR: a vehicle signal booster that lets you stay connected with less dropped calls and better data/voice quality. The device is compatible with T-Mobile, Verizon, AT&T, and other popular US networks. It can boost signals up to 32x.
This cell phone signal booster works for 4G LTE, 3G, and 2G network signals. It seems pretty easy to install too. Costs under $450.