▁in ▁the ▁proposed ▁tri o ▁of ▁similarly ▁advanced ▁un ib ody ▁cars . ▁The ▁I - type ▁ 1 2 - 4 ▁( ess entially ▁the ▁same ▁as ▁the ▁ 1 0 - 4 ▁but ▁with ▁a ▁longer ▁wheel base ▁and ▁an ▁en larg ed ▁engine ) ▁was ▁introduced ▁in ▁September ▁ 1 9 3 8 ▁and ▁the ▁J - type ▁ 1 4 - 6 , ▁replacing ▁the ▁old ▁Light ▁Six , ▁was ▁introduced ▁the ▁following ▁month ▁but ▁sales ▁did ▁not ▁begin ▁until ▁early ▁ 1 9 3 9 . ▁This ▁advanced ▁three - model ▁range ▁was ▁very ▁well ▁received ▁by ▁critics ▁and ▁buy ers ▁and ▁placed ▁V aux hall ▁in ▁the ▁v angu ard ▁of ▁autom ot ive ▁engineering ▁for ▁the ▁mass ▁market ▁in ▁Britain . ▁However ▁the ▁out break ▁of ▁the ▁Second ▁World ▁War ▁in ▁ 1 9 3 9 ▁greatly ▁restricted ▁the ▁sales ▁of ▁all ▁new ▁cars ▁just ▁as ▁the ▁new ▁V aux hall ▁range ▁was ▁entering ▁the ▁market ▁and ▁production ▁was ▁reaching ▁full ▁flow . ▁Car ▁production ▁was ▁ceased ▁entirely ▁in ▁May ▁ 1 9 4 0 , ▁by ▁which ▁time ▁over ▁ 5 0 , 0 0 0 ▁ 1 0 - 4 s , ▁ 1 0 , 0 0 0 ▁ 1 2 - 4 s ▁and ▁ 1 5 , 0 0 0 ▁ 1 4 - 6 s ▁had ▁been ▁built . ▁ ▁During ▁the ▁Second ▁World ▁War , ▁car ▁production ▁at ▁L ut on ▁was ▁susp ended ▁to ▁allow ▁V aux hall