New car registrations – a proxy for sales – slumped to 567,308 vehicles last month, compared to over 1.2 million during the same month last year, the European Automobile Manufacturers Association (ACEA) said.
"All 27 EU markets contracted in March, but Italy took the biggest hit, with registrations falling by 85.4% to 28,326 new cars," ACEA said.
France was also particularly hard hit with a 72.2% drop, as was Spain where sales tumbled 69.3%.
In Germany, where restrictions have been less onerous, sales fell by 37.7%.
For the first 3 months of the year, sales were down by 25.6% to 2.48 million vehicles.