Illegal, yes.... worthwhile to challenge via the legal process... a big MAYBE...?
Time and cost become factors... the car in question is 8 years old, with 95 000 miles, and a resale value of about $ 1000 bucks... give or take.
The owner says that the car maker is being sticky about a couple of undocumented oil changes... and as we all know, there are two sides to every story...
And those who follow the "by the book ... " dealer maintenance schedule will often end up paying for any "warranty..." claim anyway, thru excessive maintenance costs. Inspect and adjust, rotate tires and change oil ... that'll be $ 200.00... !?!?
Same thing for the guy who pays for an extended warranty... I checked the Toyota . ca website recently, and discovered that extending the comprehensive warranty 2 years out to 5 years to match the drivetrain warranty was $ 2000.00 ...! Or, extending out to 7 years , 200 000 km is a whopping $4500.00...
That $ 2 grand + would pay for a chunk of repairs, IF something should fail. Buying the warranty means they get your money up front. Not getting it means they MIGHT get your money...