The vintage era in the automotive world was a time of transition. The car started off in 1919 as still something of a rarity, and ended up, in 1930, well on the way towards ubiquity. In fact, automobile production at the end of this period was not matched again until the 1950s. In the intervening years, most industrialized countries built nationwide road systems with the result that, towards the end of the period, the ability to negotiate unpaved roads was no longer a prime consideration of automotive design. Cars became much more practical, convenient and comfortable during this period. Car heating was introduced (progressing from hot bricks via double-skinned exhaust manifolds to the heater radiator matrix), as was the in-car radio.