I am absolutely not a lawyer, but…
This sounds remarkably like false imprisonment.
Note that the vehicle doesn’t need to be autonomous. In fact, CA PEN §§ 236 seems pretty broad on the face of it:
False imprisonment is the unlawful violation of the personal liberty of another.
Full stop. And, per CA PEN §§ 237(a),
False imprisonment is punishable by a fine not exceeding one thousand dollars ($1,000), or by imprisonment in the county jail for not more than one year, or both
