Car sales in the U.S. likely went up about ten percent last month, compared to the same month a year ago.
U.S. sales for April will be reported Tuesday.
Analyst Jesse Toprak of Truecar.com says sales would have been better, but the disasters in Japan greatly diminished the supply of car parts, especially for Honda and Toyota.
Both companies have drastically slowed production of cars, and the slowdown could continue through the rest of the year.
Toprak says Japanese car companies typically do well when gas prices increase.