The agency won the business after a competitive pitch against a number of the car manufacturer's global roster agencies.
It will now be briefed to create an integrated global campaign to launch the car across business-to-consumer and business-to-business channels.
The news comes as the agency attempts to retain the company's £16m above-the-line UK account.
Lining up against the agency, which is pitching as part of Engine, are VCCP, Karmarama with Meteorite and The Brooklyn Brothers. The process is being handled by the AAR.
BMW is also poised to put its media planning and buying account, which is handled by Vizeum, up for pitch.
In January, BMW announced that UK car sales for the month had grown by 17 per cent year on year to 82,120 and that it was targeting full-year sales of 1.3 million.
The car manufacturer put this growth down to high levels of sales of the new BMW 5-Series and the Mini Countryman.
The company's core BMW brand posted car sales of 69,852, a growth of 16%.
WCRS refused to confirm or deny the win.