You’ll have to go online for Idaho. Each state is a little different. In mine, yes you’d need a personal property tax receipt, even if it was paid. Should all be in the glovebox I’d think from his last time registering.

Up here you can get away from the taxes if the vehicle was gifted to you on his passing, you might have a clause like that in the states as well, but you will have to check, with your state to see if you can.

Check to see what the inheritance laws are in your state.