Unfortunately, the increase in March did not continue.
Used car sales fell sharply in April 2017. 

Occasion sale April 2017 comes to 89.032 occasions

In March 2017, car dealers sold 101.060 used cars to consumers.
This is evident from figures from the VWE. The days off on Easter Monday and King's Day may have something to do with this.

All figures from April 2017

  • 89.032 used cars sold in April 2017;
  • that is 9,1% less than in April 2016 (97.994 units).
  • Total number of used cars sold in the first four months of 2017 is 372.684;
  • that is a decrease of 3,4%% compared to the first four months of 2016 (385.728 units).

Source: VW extension