Vehicle pre-registrations rose by 46% in June compared, according to research conducted by automotive data company cap hpi.
The research showed a jump in the volume of 16/16 plates in June, assessed by used vehicles advertised on digital platforms.
"Pre-registered vehicles must be kept for 90 days before sale," said Philip Nothard, Black Book editor, consumer and retail. "A spike in 16/16 plates at the end of June is indicative of activity at the end of March."
In June, volumes of 16/16 plates compared to 15/15 plates in the previous year rose by 10%. The demand for used cars has remained strong in 2016, with Q1 experiencing a 13% increase compared to last year, the largest quarterly sales increase on record.
In the first three months of the year, 1,975,945 used cars were sold, falling just short of the largest on record of 2,005,660 in 2004.
There are concerns that a jump in 16/16 vehicle plates may bode ill for the older vehicles in the used market, as nearly-new cars may better compete with fresh vehicles.
"There may well be a knock-on effect to older cars as a consequence of the price-points of nearly-new to compete with the strong new car offerings available," continued Nothard.
Furthermore, the recent strength of the used market is unlikely to shield it from the traditional slump of the summer months.
"We tend to see some price erosion take place through July," said Nothard. "There may be some easing of retail demand, due to the holiday period."