CA: 3 Wheeler Licensing

[Dolmen]

This business with Gov. Schwarzenegger supposedly riding illegally has brought up some questions about CA licensing, I've had a good search through the California Vehicle Code, but can't seem to find a definitive answer.

Can any CHP/LAPD or other California cops answer this question?

Exactly which license is required to operate;
a: A motorcycle with sidecar.
b: A purpose built three wheeler like the concept VW GX3.

The CVC specifies a motorcycle as "a vehicle designed to travel on not more than 3 wheels and having a GVW of under 1500 lbs", but the C endorsement also specifically excludes "two wheel motorcycles", rather than just excluding "motorcycles" which I would expect, the C endorsement also doesn't seem to specify number of wheels, just axles (and axles are defined essentially as a shaft that holds a wheel or wheels and supports the vehicles weight).

Thanks.

[Dolmen]

After rummaging around in the CVC, it seems that an M1 endorsement is only required if the motorcycle only has 2 wheels.

It's possible for a motorcycle to have 3 wheels but still be covered under a C endorsement.

I guess this also means that the lightweight 3 wheelers can use the HOV lane and must still require a helmet when driving.