The way a coverage section is built matters as much as the parts it mentions. Two contracts with long, impressive-looking lists can behave very differently once a part fails.
Named components
A named-component contract lists the parts it covers. If a part is not on the list, the contract does not cover it, and whether the part failed in a normal way makes no difference. Read the list line by line and look for the components you worry about most, such as electrical modules, sensors, seals, pumps, and hoses. Missing parts are the gap. Ask the provider whether the list is complete or only a sample of what it covers.
Exclusion lists
An exclusion-style contract starts from the idea that most mechanical parts are covered, then names what is left out. The clauses that matter most are the exclusions. Look for items excluded because they wear out, items excluded because of a use rule or a condition, and general language that excludes any part that fails as a result of an excluded part. Those general clauses are where disagreements usually start, so read them slowly.
How to tell which one you are holding
Start with the coverage clause. Words like only, limited to, and listed components point toward a named list. Phrases like covers all parts except, or the following are excluded, point toward an exclusion list. Then ask the provider which structure the contract uses and whether it has a complete parts list in writing. Choose a few parts you have actually replaced on a car before and check each one against the contract. Keep your notes side by side when you compare two providers, so the differences are visible on one page.
If you want to see how this site weighs published terms before you read the comparison tables, the How We Score Vehicle Service Contract Companies page explains what we look at and what we leave out.