U.S. sales of cars and trucks are expected to rise 19 percent in April as customers worried about shortages of Japanese cars rushed to buy the models they wanted.
Automakers release monthly sales results Tuesday.
In March, sales jumped 17 percent from a year earlier to 1.25 million. That healthy rate showed the auto industry's steady recovery remains on track.
April could be the last big sales month for a while as automakers start to run short of models, mainly small and midsize cars.
Some car production is being limited because companies in North America are running low on supplies from Japan.
Those supplies include paint pigments. They are made in factories damaged or disrupted by the March 11 earthquake and tsunami in Japan.