my audi TT had a mandatory recall. i had to take it to the dealership to have a spoiler installed, FREE!

the reason was the design without the rear spoiler lost traction in the rear end from lift at @ 70 mph.
they had a few cars actually flip. So audi issued spoilers for every audi TT produced.

the new audi TT's have the retractable spoiler.

there are other examples. like the new beetle. when they made the turbo S version, it was capable of going fast enough that the factory put a retractable spoiler on it.

Factory is not "rice". Even on a Japanese car. However, a lot of people in the VW scene feel that the cobalt SS and even the STI wings are rice, because they are not "needed" aerodynamically.