These were made for Mattel by Irwin. It was not made by Mattel. The Irwin Toy Co. made all of the first series of Barbie cars, thru the early '70s..
Plus, this same chrome steering wheel & windscreen came on the '62 Austin and the '64 & '68 Mercedes'. The Mercedes was reissued in '68 in Turquoise, Red and at Sears only in Baby Blue, but '68s all came with white steering wheels..
PS; the rarest Barbie car is a RED MERCEDES, made from the same mold as the '64s. And next rarest is a Red Dune Buggy that had the '63 Hot Rod's wheels & roll-bar, but w/a different windscreen..
The Mattel made Dune Buggy's are worth nothing. The 1960s Irwin made Barbie cars, although cheaply made, bring the highest prices. Irwin cars issued as Irwin cars, like the green Mercedes, came w/o windscreens and are worth very little..
jeff