▁ac oust ical ▁double - panel ▁roof , ▁t ighter - f itting ▁glass , ▁flush ▁style ▁outside ▁door ▁handles , ▁m old ed ▁full ▁fo am ▁front ▁and ▁rear ▁seat ▁construction , ▁flow - through ▁power ▁vent ilation ▁system , ▁inside ▁h ood ▁release , ▁ref ined ▁Del cot ron ▁generator ▁and ▁se aled ▁side - term inal ▁battery , ▁a ▁larger ▁ 2 2 ▁gall on ▁fuel ▁tank , ▁and ▁" flush ▁and ▁dry " ▁ro cker ▁pan els ▁introduced ▁first ▁on ▁the ▁red es igned ▁ 1 9 7 1 ▁full - size ▁G M ▁cars . ▁Another ▁struct ural ▁improvement ▁was ▁a ▁stronger ▁design ▁for ▁the ▁side ▁door ▁guard ▁be ams . ▁Options ▁included ▁sw ivel ing ▁Str ato - bucket ▁seats ▁( with ▁console ) ▁for ▁coup es , ▁a ▁power ▁moon ro of , ▁and ▁Tur bine ▁I ▁u re th ane ▁( back ed ▁by ▁steel ) ▁whe els , ▁as ▁was ▁the ▁instrument ▁gauge ▁cluster . ▁ ▁The ▁Old sm obile ▁C ut lass ▁( including ▁the ▁Hur st / Old s ▁and ▁ 4 4 2 ) ▁changed ▁body ▁styles ▁to ▁the ▁" Col onna de " ▁body ▁style , ▁which ▁was ▁used ▁until ▁ 1 9 7 7 . ▁The ▁Hur st ▁Old s ▁was ▁based ▁on ▁the ▁semi - fast back ▁C ut lass ▁S ▁cou pe ▁and ▁featured ▁an ▁interior ▁with ▁sw ivel ing ▁Str ato ▁bucket ▁seats ▁separated ▁by ▁a ▁console ▁with ▁Hur st ▁D ual - G ate ▁sh