Model-level reading
What changes the warranty calculation
The Nissan Altima file contains 11 model years and 2,645 submitted complaints. The middle year in this set has 154 reports, giving each annual count a model-specific reference point.
2015 has the largest complaint count in the current file at 942. That does not establish a defect rate because sales volume and vehicle age differ across years.
Engine replacement or major internal repair carries the highest midpoint parts estimate among the applicable repair categories at $7,000. I would check whether that system remains under factory coverage before pricing an extra contract.