Do headlight replacement problems track forest and woody wetland share of land across states?
Across U.S. states, NHTSA owner complaints about headlight replacement run higher where forest and woody wetland share of land is higher, after adjusting for the makes sold in each state. This is an association across states, not proof that forest and woody wetland share of land causes this repair.
State reports of this repair against forest and woody wetland share of land, one dot per stateEach dot is a state: how much more (or less) than expected this repair is reported there, adjusted for the makes sold in the state, against its forest and woody wetland share of land (NLCD 2021, state median county)
How to read it: Each dot is a state. Further right means more forest and woody wetland share of land (nlcd 2021, state median county); higher up means more complaints for this repair than expected (1.0 is average). If the dots climb to the right, reports of this repair rise with forest and woody wetland share of land (nlcd 2021, state median county).
What it shows: States with more forest and woody wetland share of land (nlcd 2021, state median county) tend to sit higher on the chart across 48 states: a pattern in the data, not proof of cause.
Data: USGS NLCD 2021 Land Cover via the MRLC service, joined to NHTSA owner complaints, downloaded 2026-10-06 · 48 states. Chart: CalcScrape · calcscrape.com
The 10 states with the most forest and woody wetland share of land (New Hampshire, Vermont, Maine, West Virginia, Connecticut, Alabama, Mississippi, Pennsylvania, Virginia, New York): reports of this repair run 22% above what the makes sold there would predict, and 8 of 10 are above expected. The 10 with the least (South Dakota, North Dakota, Nebraska, Kansas, Iowa, Nevada, Texas, Arizona, Wyoming, Minnesota): 4% below, and 4 of 10 are above expected.
Exceptions: Connecticut and Mississippi are among the highest in forest and woody wetland share of land but report below expected; North Dakota (51% above expected) and Wyoming (54% above expected) are among the lowest but above expected.
Split the states into thirds: the third with the least forest and woody wetland share of land runs 9% below what the makes sold there would predict, the middle third 0% above, and the third with the most 18% above. It steps up steadily.
For forest and woody wetland share of land, after allowing for the 1562 comparisons we ran, luck alone would produce a pattern this strong about 1 time in 16. Take out any single state and the forest and woody wetland share of land pattern still holds.
Trees drop sap, leaves, pollen and branches on parked cars, which marks paint, clogs wipers and cowls and loads cabin and engine air filters.