Six countries show increases, ranging from 0.5% in Luxembourg to 26% in Finland.
For the month of December, Western European new cars sales were down 1.8% compared to the same month in 2002.
The ACEA said: 'National figures for the month point to a progressive recovery in most countries. Eleven out of 15 EU countries posted increases, ranging from 0.6% in France to 44.7% in Belgium.
'In contrast, only three countries showed decreases, but these were fairly significant ones - Italy (27.5%), the Netherlands (43.7%) and Ireland (52.7%).
'In the case of Italy, it can be explained by the comparison with a very strong month in December 2002 (+51.4%), when the incentive scheme for phasing out older cars was coming to an end.'