This paper presents mobile-to-mobile (M-to-M) channel measurements and models at 1.85 GHz in dense-scattering suburban areas. Three test scenarios were considered for different transmitter (Tx) and receiver (Rx) antenna placements. Scenario 1: inside-vehicle-to-inside-vehicle (IV2IV), where both Tx and Rx antennas were placed inside the test vehicles; Scenario 2: inside-vehicle-to-walk (IV2W), where the Tx antenna was placed inside the vehicle and the Rx antenna was inside the pocket or next to the face of the tester; and Scenario 3: walk-to-walk (W2W), where the Tx and Rx were moving at walking speeds, the Tx antenna was placed on a test cart, and the Rx was inside the pocket or next to the face of the tester. To mimic more typical M-to-M channels in practice, eight sub-scenarios were configured under the availability of the line-of-sight (LoS) between the Tx and Rx. Detailed channel models are proposed for path loss, shadowing, small scale, and multi-scale fading based on the collected measurements. The level crossing rate (LCR) and average fading duration (AFD) are studied from the measurements and compared with the theoretical expressions.