New-vehicle sales are expected to total 1.63 million units in March, a 3% year-over-year increase, resulting in an estimated 17.4 million seasonally adjusted annual rate, according to Kelley Blue Book.

Adding the projected 1.63 million units in March to the January and February’s totals would bring the first quarter’s total units sold to 4.1 million units, according to the firm. Although this would only be a 0.3% year-over-year increase, it would still mark the second-best first quarter on record, in terms of sales, the firm added.

"Kelley Blue Book expects manufacturers to report mostly positive sales numbers this month, capping a steady first quarter with an average SAAR of 17.4 million," said Tim Fleming, analyst for Kelley Blue Book. "Despite considerably higher discounts and incentives, first quarter sales totals will likely only finish flat versus last year, a signal of weakening consumer demand for new vehicles. As sales cool after years of robust growth, adjusting production accordingly and managing supply, especially in car segments, should be top priorities for automakers."

Retail sales are expected to account for 77.9% of new-vehicle volume in March, a 1.1% increase over last year, according to KBB data. This potential retail increase leaves a slightly smaller chunk of the pie available for fleet during the month.

According to KBB, General Motors is expected to gain the most market share in March. The OEM’s SUV lineup, in particular could grow sales by 25%, KBB added. GM trucks are also expected to perform better in March compared to the same time last year. GM Trucks could potentially increase sales by 10% in March, thanks in large part to incentives, according to KBB.

On the other side of the spectrum, Ford is poised to see the biggest sales decline, driven primarily by a decline in fleet sales, according to KBB. Ford Fusion and Ford Focus models could potentially see declines of more than 20%. Sales of other popular fleet vehicles like the Ford Transit could also fall by 20%.

Looking at the industry as a whole, the consumer shift from cars to SUVs is expected to continue. Double-digit growth for popular compact and mid-size SUV/crossover segments is expected, according to KBB.

"Mid-size cars continue to suffer as a result of shifting consumer preference toward utility vehicles, and Kelley Blue Book anticipates the segment will lose nearly 3 percentage points of market share," said Fleming. "This segment, which was the top-selling category in the industry as recently as 2013, is in a rapid decline, which does not bode well for the upcoming redesigns for the Toyota Camry and Honda Accord, due later this year."