). ▁ ▁V aux hall ' s ▁sales ▁began ▁to ▁increase ▁from ▁ 1 9 7 5 , ▁with ▁the ▁launch ▁of ▁two ▁important ▁new ▁models , ▁the ▁Che v ette , ▁a ▁small ▁three - door ▁h atch back ▁that ▁was ▁the ▁first ▁car ▁of ▁its ▁kind ▁to ▁be ▁built ▁in ▁Britain , ▁and ▁the ▁Caval ier , ▁a ▁sty lish ▁four - door ▁sal oon ▁designed ▁to ▁comp ete ▁head - to - head ▁with ▁the ▁all - con qu ering ▁Ford ▁Cort ina . ▁A ▁two - door ▁cou pe ▁and ▁three - door ▁" s port ▁h atch " ▁had ▁joined ▁the ▁Caval ier ▁range ▁by ▁ 1 9 7 8 , ▁but ▁there ▁never ▁was ▁an ▁estate ▁version . ▁The ▁Caval ier ▁helped ▁V aux hall ▁reg ain ▁lost ▁ground ▁in ▁this ▁cru cial ▁sector ▁of ▁the ▁market , ▁while ▁the ▁Che v ette ▁proved ▁to ▁be ▁h ug ely ▁popular ▁in ▁the ▁growing ▁super min i ▁sector , ▁as ▁more ▁buy ers ▁turned ▁to ▁smaller ▁cars ▁following ▁the ▁oil ▁crisis ▁of ▁ 1 9 7 3 . ▁The ▁Che v ette ▁range ▁later ▁evol ved ▁into ▁a ▁three - door ▁estate , ▁as ▁well ▁as ▁sal o ons ▁with ▁two ▁or ▁four ▁doors . ▁Both ▁models ▁were ▁based ▁on ▁models ▁produced ▁by ▁Op el , ▁G M ' s ▁German ▁subs idi ary , ▁the ▁Che v ette ▁being ▁based ▁on ▁the ▁Op el ▁K ad ett , ▁but ▁with ▁a ▁distinct ▁front ▁end . ▁Al ong