I'm assuming you are in the states.. but that may be incorrect.. Aftermarket warranties are really "sus".
This is verbiage from a top level "Diamond" plan from a 3rd party - which you have to start asking yourself.. wth do they actually cover....
"This CONTRACT covers all components of the VEHICLE, EXCEPT for the following items:
EXCLUDED FROM COVERAGE:
Replacement of maintenance parts or services regardless of when they occur during the CONTRACT, including but not limited to:
i. Brake Pads, Shoes, Rotors and Drums;
ii. Shocks and Struts;
iii. Rubber Hoses;
iv. Serpentine Belts;
v. Wiper Blades;
vi. Headlamp Bulbs;
vii. Oil Changes;
viii. Air Filter;
ix. Timing Belts;
x. Tune-Ups;
xi. Lithium-ion or Hybrid Batteries.
BREAKDOWNS resulting from engine sludge, carbon, pre-ignition, detonation, varnish, corrosion, foreign objects, dirt, dust, liquid, cracked rubber and/or neoprene parts, dry-rot, road chemicals, lack of proper fluids or use of additives or fuel grades not recommended by the manufacturer. Failures to the Air Bags, Seat Belts, or Supplemental Restraint Systems.
BREAKDOWNS caused by external causes and acts of nature including, but not limited to: collision, road hazards, vandalism, theft, fire, earthquake, tornado, flood, hurricane, lightning, rust,
BREAKDOWNS due to gradual loss of performance and resulting from normal operation and use (due to VEHICLE mileage and/or age) unless worn beyond manufacture tolerance, including, but not limited to: valve guides, valves, piston rings, transmission clutch pack discs and bands.
Any adjustments, repositioning, refitting, realigning, programming and/or cleaning, unless required as a result of a COVERED BREAKDOWN.
Paint; carpeting; upholstery; fabric; VEHICLE frame; the following parts of the manual/hydraulic clutch assembly - friction disc, pressure plate, throw-out bearing and pilot bearing; moldings; distributor cap/rotor; wheels and wheel covers; seat belts and retractors; clock spring; battery and cables; rubber body parts; VEHICLE body panel and components; trim; weather stripping; tubing; illumination of any kind, including but not limited to - lenses, light bulbs, headlight and/or tail light assemblies, LED lighting and sealed beams; exhaust system; keyless entry transmitters; brake pads, drums, rotor, and shoes; canvas; fiberglass, vinyl or fabric tops; remote compact disc changers; buttons; handles; door hinges; glass and glass assemblies; audio components not installed by the factory; CB radios; bright metal; sheet metal; bumpers; ornamental moldings; welds; winch; diesel emissions filter elements; evaporative emissions canister; spark plugs and wires; glow plugs; wheel balancing; hoses; Serpentine and V-belts; wiper blades; restraint belts; struts; strut bearings, mounts, and housing; shock absorbers; interior and exterior trim items; carburetor; body seals and gaskets; plastic and framing. Any part that the original vehicle manufacturer has provided a replacement, maintenance or limited-service life or replacement interval for."