I attend, weather permitting:), a group called Euro Sunday: http://www.eurosunday.net/index.html.
They meet at various locations around the Sacramento area on the fourth Sunday of the month. It's early...8-10AM...so you'd need to leave Tahoe at "oh-dark-thirty".
After the low key get together, there is often a planned tour/drive to another location, sometimes for lunch, etc.
Other than that, I take the 7 to the Auburn Cruise Nights (2nd Friday May-Sept) in downtown Auburn. But they take only pre 1972 cars.
http://www.auburncruisenite.com/ for details and history photos.