I'd have to check (this is a case where ATF has jurisdiction) but I believe it is perfectly legal to transport adult beverages for your own PERSONAL use (and if you happen to trade some away, you are not profiting and a liquor license does not apply) - but this is something to be checked out at atf.treas.gov. I'd do it myself, but I don't drink beer, and I won't be able to make 20th - maybe 25th? Too much going on in Octember, and lack of funds - anything I don't spend on classes or those damned expensive textbooks at De Anza will likely go into the XJ for a few things I'm tossing about...
Again - the key is usually personal use. Since booze isn't at tightly restricted as other things, it shouldn't be too bad.
Bear in mind that ATF has original jurisdiction on these regs, unless the locals have their own laws (something else worth checking.) The only place I've ever known F Troop to be out trolling is major gun shows or Knob Creek - elsewise, they pretty much keep to themselves on issues like this (they get more for firearms busts like ClassIII and no-FFL than they do on booze, plus they have an institutional fear of citizens owning firearms in the first place...) As mentioned, local fuzz isn't in the business of enforcing Federal law, and cannot cite you without clearning it with the Feds in the first place, and receiving persmission to do so from the originating agency (F Troop, USSS, FBI usually.) I can't think of a cop willing to put his number out on NALEMARS for something petty like this, but I don't know for certain...
5-90
(NALEMARS - North America Law Enforcement Mutual Assistance Radio Service - used for interagency co-ordination when the Feds are involved or over "regional" areas. Not to be confused with lesser networks lik CLEMARS in California...)