I don't know if they have a car-2-car frequency that they exclusively use, but I do know that when everything goes down they'll be on CHP Gold or Black, or come up on City or Sheriff talkgroups.
SACCATS is a mult-agency program hosted primarily by CHP. A while back SSD left SACCATS and created their own division called ACE. Auto Crimes Enforcement. Since it's multi-agency, you'll find SACCAT untis on just about any radio system in the region, just depends whose working on the team and where at that particular time. They still come up on SSD radio from time to time. Check for CHP Gold, Black and Tac channels. They aren't very heavy radio users since most of their activity is detective type work and stationary stakeouts.