Dave, the Phaeton vent/shield arrangement looks very effective, but pretty
much work to fit.
The RS3 element will do its work properly if the shield is removed. Remember
the air stream under the frontal area of the car isn't moving in a straight line,
but more like a 'V' passing the wheels and brakes. That is why the RS3 vents
are positioned that way. Even more it's cheap and simple.
I ever wanted the RS4-2 as I now some guys using them and they are very
happy with them. Since the boys from Raeder Motorsport first told me about
Endless I just hear and read good things about them. They last at least three
times longer and the disc at least two times. But I still tend to go for the Pagids.