The supply curve for cars will be more elastic the:

greater the quantity demanded.

longer the time interval considered.

greater the decline in input prices.

less able producers are to make other goods.

The supply curve for cars will be more elastic the longer the time interval considered. Firms often produce multiple products. It takes time, however, to re-allocate resources to the different products. As the price of one of the products changes, the firm will switch around their resources to more/less profitable goods and services. Because of the time it takes to make this change, however, the effect will be longer over the longer period of time. So the longer the time period, the more elastic the supply will be since the firm will have longer to make the adjustment.