Aero250, must admit I never had an issue with earthing on my S1 in the 9 years I had her. That said the car led a pampered life and was never exposed to a salty or high humidity environment so perhaps my experience not typical.
MAF failure yes, but then we had driven through a massive rainstorm and probably water got into the airbox.
Clicking starter also but always down to the starter. Incidentally, and you'll find it on another post off mine, and good friend in the UK who's had his S1 since new no longer suffers the dreaded click and garages his car in a dehumidified garage. Clearly the contacts are very sensitive to humidity levels.
Cheers
