I am very concerned about the impending implementation of the Ultra Low Emission Zone (ULEZ) in London. It will expand to the inner north and south circular roads in 2021. To comply with ULEZ, all cars have to be EURO 4 compliant.
I know it is over 2 years away, but quite unfortunately, I may need to sell my beloved Fiat 126 Bis and my Alfa Romeo GTV well before then.
I think there is no a way to upgrade these cars to EURO 4. For my Alfa Romeo, I don't it is a straight catalyst converter upgrade or modification.