0 s ▁with ▁the ▁early ▁ 1 9 6 0 s . ▁The ▁pre - per formance , ▁post - war ▁era ▁of ▁practical ity ▁in ▁the ▁early ▁ 1 9 5 0 s ▁gave ▁emphas is ▁to ▁more ▁econom ical ▁sed ans , ▁so ▁it ▁is ▁notable ▁that ▁early ▁prom ot ional ▁model ▁mak ers ▁commonly ▁m old ed ▁vehicles ▁in ▁ 4 - door ▁configurations ▁even ▁in ▁the ▁most ▁basic ▁models ▁available . ▁Four - door ▁Bel ▁Air s ▁were ▁offered ▁by ▁PM C ▁all ▁the ▁way ▁up ▁to ▁ 1 9 5 8 , ▁one ▁available ▁with ▁police ▁decor . ▁It ▁is ▁interesting ▁that ▁PM C ▁also ▁did ▁a ▁ 1 9 5 8 ▁Che v ro let ▁in ▁two - door ▁style , ▁rein for cing ▁the ▁tr end ▁that ▁by ▁about ▁ 1 9 6 0 ▁most ▁prom ot ional ▁mak ers ▁only ▁mode led ▁sport ier ▁and ▁more ▁powerful ▁ 2 - door ▁coup es ▁and ▁hard top s . ▁However , ▁a ▁m old ed ▁red ▁four ▁door ▁did ▁became ▁a ▁Fire ▁Chief ▁car . ▁This ▁was ▁in ▁line ▁with ▁the ▁newer ▁era ▁of ▁a ▁stronger ▁economy , ▁more ▁aff lu ent ▁client ele ▁and ▁the ▁on set ▁of ▁the ▁new ▁baby - bo omer ▁driver ' s ▁market . ▁ ▁America ' s ▁first ▁sports ▁car , ▁the ▁ 1 9 5 4 ▁Cor v ette , ▁was ▁made ▁by ▁PM C . ▁ ▁It ▁was ▁produced ▁with ▁a ▁remov able ▁sports ▁hard top ▁(