Cars fall under cost based adjustments. This is the most recent (AFAIK) document the BLS has published: https://www.bls.gov/cpi/quality-adjustment/new-vehicles.pdf

It's not entirely an unfair point in the sense clearly a modern car with modern safety and electronics costs more to produce (hence the cost basis). But as far as I know the BLS is basically given free reign to invent the cost basis.