I received a car as a gift. Do I need to report this anywhere and/or pay Wisconsin sales or use tax on the vehicle?

[pk]

If received from non-foreign person  then NO. If this is really payment in kind and not gift, then you have to report  and possibly pay taxes.

Whether you have to pay Wisconsin USE tax , depends on the exact transaction -- pure gift, even if received in another state does not come under USE tax -- you may have to register and title in Wisconsin.