You can get different coverages based on when you buy the vehicle, the age, mileage etc.
One thing is for certain though. Since your car is aleady out of dealer warranty, the problems you have now will not
be covered under an extended warranty you buy, because they would fall into the "pre-existing problem" clause on any contract.
I don't want to discourage you from looking into one, but know that even if you do get one, you're only covered for new problems.