So if the Aero's get these bubbles what is the remedy?
As I understand it Michael there isn't one short of preventatively replacing the mounting gaskets for the rear lamps. As John explains below, it's moisture getting into the seal around the lamp unit that is the cause, not salt/moisture being thrown up under the car - but the good news is that it is scarcely noticeable, develops slowly and can be treated by a good paint shop if it gets to a point where it bothers you.
The corrosion points on the aeros around the light are where the steel light fixings are fixed to the aluminium body. The sponge that holds the light restains the moisture and maybe road salt and this the results in some for electrolysis and paint erosion.
All the aeros I've seen with paint corrosion have had it occur in the same places.
