If the Bottoms all Look the same since fyrffytr1 I'd'd the Buick.
I'd say they are all Friction Cars.
Friction Cars can be Pushed across a Carpet and when you Let go it will Move.
I Think the older ones You Pulled Backwards and Let Go & They Moved Forward.
at least That's how I remember my First one.
they have been around since the 50's at least and were approximately 20 inches long