<Tr> <Th> Buick </Th> <Td> 4,858,961 </Td> </Tr> <Tr> <Th> Oldsmobile </Th> <Td> 3,745,648 </Td> </Tr> <Tr> <Th> Pontiac </Th> <Td> 3,706,959 </Td> </Tr> <Tr> <Th> Mercury </Th> <Td> 2,588,472 </Td> </Tr>

What were cars made of in the 1950's