I heard from some folks in SAC that all new CHP motors are being equipped with a special Pyramid P-750 unit (P25).
It operates on 774.53125 simplex, versus the duplex VRS System found in the upgraded CPVE cars, and every officer is issued a new EF Johnson 5100ES portable. It appears that it will function similar to the current VHF-H extender system, but P25. And the frequency does appear to be a base channel, which seems to indicate that only offices without motors can effectively use 774.53125 (CHP Base CH 5), once the 700 MHz CHP Base system is deployed.