After the taxi Dorothy, Scarecrow, Brian, and Nick lands on the you can see a car topper mention rides to Oz. When the Wicked Witch blast Dorothy with her umbrella the topper on the taxi is no longer there. Then when Glinda appears the topper is back on the taxi.
When Dorothy lands in Oz and opens the house door, the door hardware is definitely not the kind that would have been used in 1899.