As of 16 January 2017 all cars entering Paris have to have a Crit'Air sticker. This also applies to foreign cars in the city for a visit; sadly ALL vehicles registered before 1 January 1997, will be banned from the city's streets between 8am and 8pm, Monday to Friday! So it is a weekend only rally or after 8.00pm!
Later vehicles fall into half a dozen categories:
Green (Crit'Air) for a electric or on-the-road hydrogen car;
Violet (Crit'Air 1) for a hybrid or petrol registered in 2011 or later (Euro 5 and 6 standard);
Yellow (Crit'Air 2) for a petrol from 2006 to 2010 (Euro 4) or diesel from 2011 (Euro 5 and 6);
Orange (Crit'Air 3) for a petrol from 1997 to 2005 (Euro 2 and 3) or a diesel engine from 2006 to 2010 (Euro 4);
Bordeaux (Crit'Air 4) for a diesel engine from 2001 to 2005 (Euro 3);
Grey (Crit'Air 5) for a diesel engine from 1997 to 2000 (Euro 2)
and I thought it was not quite yet April 1st!
PS You cannot order one of the stickers for delivery to the UK until February......
French cars only at present.
Brian RJ