The high-profile launch of the new version of the Cowley-built Mini has been dogged by an engine problem.
Customers who ordered the diesel version of the Cooper model have been told they will have to wait until a noise issue is cured.
The third-generation Mini went on sale on March 15. A total of 4,500 customers had placed orders by that date.
A total of 100 customers who expected to take delivery of the cars when they went on sale last month have been affected.
Mini spokesman Piers Scott said: “It is a small component which stops engine shock.
“We had not identified the issue prior to it going into customers’ hands.”