Repairing a car after a crash—if it’s possible—requires an assessment of the damage and a decision about which parts to replace. Today Volkswagen must tell regulators in Germany how it intends to put right 2.8m diesel-engined cars with software designed to cheat tests for nitrogen-oxide emissions. Yesterday VW’s new boss, Matthias Müller, told a German newspaper it will rectify the fault by the end of 2016: that could mean a simple software patch, or replacing entire engines or vehicles. Even if the German carmaker gets away with an easy fix at home, it may be less lucky elsewhere: abroad, 8.2m affected vehicles are on the road. The costs of lawsuits and lost business lie ahead. France and Italy have launched their own investigations; if VW fiddled European tests as well as American ones, the bill will be higher still. No wonder Mr Müller warned workers yesterday of deep cuts to come.