As dealers prepare to sell down their inventory of model year 2019 cars to make way for new 2020 models, they’re still trying to get rid of leftover 2018 inventory. That’s... not a great sign.

A full 3.5 percent of all July 2019 sales were 2018 model years, according to J.D. Power PIN transaction data provided by Tyson Jominy, their VP of Automotive Data and Analytics Consulting. That’s up from 2.5 percent last year and the highest since at least 2005, the first year for which J.D. Power has data.

As Jominy explains in his twitter thread, a higher mix of 2018 cars isn’t good for automakers. For starters, automakers are spending about $1,100 more per car in incentives to move MY2018 cars than equivalent MY2019 cars. Not only that, but the high mix has contributed to a surprisingly low amount of MY2020 cars on dealer lots this late in the year.

It also speaks to an inability to match supply with demand. Clearly, sales are underperforming automaker expectations if dealers are still sitting on cars from last year.

That’s doubly concerning in a strong economy, where you’d normally expect strong demand and consumer confidence. As Jominy pointed out, the mix of previous model year cars wasn’t this high during the recession. In July 2008, for instance, only 0.9 percent of all new car transactions were MY2007 cars.

July, it should be noted, isn’t an outlier. Every month of 2019 so far has had an extraordinarily high amount of transactions for MY2018 vehicles. As we get closer to 2020, it’ll be interesting to see whether that leads to a cascading problem wherein pushing 2018 models leads to an abnormally slow sell down of 2019 cars.