This compares to 1,924 on the first day last year.
SIMI had previously outlined its hopes that more than 4,000 cars would be registered in the first week of the new 142 period.
In addition, 292 new vans were sold, compared to 138 on the same day last year.
Alan Nolan of SIMI comments "We knew yesterday was going to be one of the busiest days of the year for car sales, with additional cars being added to the car hire fleets, but we didn't expect such a good start compared to last year, which was the first year for the new split-registration plate. In fact, yesterday has turn out to be the highest day for new car registrations this year and nobody expected that."
