There is a difference between buying a car "as-is" and buying one with a warranty, StarMark or not. My guess is that they had the car StarMarked certified (inspected) but then didn't include the price of the StarMark warranty in the sale. This type of fault certainly would be covered in the StarMark warranty, if you had one.
If the sales manager said it was bought "as-is" that implies there is no StarMark warranty on the car.
How many miles does the car have on it. The original factory warranty is 4 years/50,000 miles, on a 99 there may possibly be warranty left on it.