Tax doesn't remove the issue, it just grabs wealth from citizens, because they can.
The cars are still in existence and being produced for sell. The fuel is no less clean.
Thing to do is leave the end user alone and stop bullying them. Phase out vehicles that are unapproved of over time. Put the money into research for an alternative fuel (that doesn't further overload our electricity supply !!!). Tackle the real problem rather than be seen to bashing the decent citizen again.