Most states allow consumption of alcohol by passengers inside limos and party buses in without any issue. And for sure in California limos and partybuses we know that you can drink on-board. The chauffeur and passengers are usually seperated by a partition and so it's pretty clear that access to "open containers" of alcohol is not an issue.
But Towncars and SUVs it is not as clear - there is no partion and so many people question if it is okay to drink in their chauffeured SUV. . . . It perfectly legal! The law that covers this is located below:
VC23229. (a) Except as provided in Section 23229.1 (minors not allowed alcohol and Limos can keep alcohol in a locked compartment in the passenger area) , Sections 23221 (passengers cannot drink) and 23223 (open container) do not apply to passengers in any bus, taxicab, or limousine for hire licensed to transport passengers pursuant to the Public Utilities Code or proper local authority, or the living quarters of a housecar or camper.
(b) Except as provided in Section 23229.1, Section 23225 does not apply to the driver or owner of a bus, taxicab, or limousine for hire licensed to transport passengers pursuant to the Public Utilities Code or proper local authority.
So bottom line it is perfectly acceptable and fine to drink in your chauffeured Orange County car service vehicle - like a Towncar or SUV. Be smart - hire an Orange County car service before you head out to your next event where you will be drinking. You can enjoy your cocktails on-board.