An NPD analyst’s letter says U.S. retail aftermarket sales grew 4% in 2018, but forecasts a different story for the U.S. aftermarket in 2019.

The analysis, from NPD executive director and industry analyst Nathan Shipley, outlines the strong year that 2018 was.

“The aftermarket industry had a solid performance over the last year, with 4 percent growth in retail sales in the 52 weeks ending November 2018. Top performing categories helping to fuel this growth have been all weather driven including washer fluids, wipers, and batteries. At the bottom of the list are categories such as interior and exterior accessories.

“These two categories along with other accessory type categories all performed poorly at retail, presumably due to a shift of consumer purchases to e-commerce. In fact, NPD’s Checkout E-commerce data shows that e-commerce sales for both interior and exterior accessories grew by 37 percent in the 12 months ending November 2018, outpacing the overall aftermarket e-commerce sales growth of 34 percent.

“For 2019, NPD forecasts that the aftermarket industry will see little to no growth. The biggest factors driving this forecast include a combination of our outlook on miles driven (flat to slightly positive), our forecast for product pricing on the shelf (continuing to increase in the 5 percent range), and Moody’s 2019 forecast for the consumer price index for new and used cars (falling).

“Separately, when looking at 2018 industry performance by month, there were several months that grew above average, in the 7 to 9 percent range, due to significant weather events. As no one can predict what weather events Mother Nature will throw our way, it is tough to post positive comparisons month over month.

“Lastly, the “uncharted territory” for our industry includes the import tariffs that were implemented in late 2018, with a planned increase of more than double in early 2019. That increase is on hold as of now, but could go into effect by the end of Q1 2019. These tariffs will have an impact on product pricing in our industry, and it will be felt directly by the consumer.

“While the aftermarket industry overall faces some challenges ahead, many categories and products will see growth this year. For brands, manufacturers, and retailers, product innovation and a focus on the in-store experience for consumers continue to be top of mind when it comes to success in today’s changing retail environment. Additionally, industry players must continue to focus on aligning their ability to get products into the hands of consumers based on how those consumers want to shop.”