Here's the update 2016 CA Firearms Laws Summary.
If one is concerned about possessing a particular firearm while transiting CA, one can always carry a handgun that has been approved for sale in CA by the CA DOJ. To check if your handgun is on the approved list of firearms that may be legally sold in CA, go here. The list is updated daily.
Adhering to the CA roster of certified handguns for sale might be an overly conservative as to what make and model of handgun a visitor might legally possess in CA while transiting.
Interestingly, Glock 43, and for that matter, all Glock Gen4s, is (are) not on the list. Yet, the Glock 43 complies with all regulatory elements of possession in CA. One simply can't purchase a Glock Gen4 or 43 in CA as of this date.
High capacity magazines purchased and/or possessed prior to 2000 are currently legal. However, since there are not any marks on magazines to identify when a magazine was manufactured, Proposition 63 passed in November, bans the possession of ALL magazines (regardless of date of manufacture) with a capacity of more than 10 rounds effective July 1, 2017.
I am not going to permanently or semi-permanently attach my locked, hard-sided case to my vehicle. A determined thief will cause even more damage to your vehicle.
Edited by Advmoto18, 23 January 2017 - 07:34 PM.