an update...
I did end up driving to the airport. Got there about midday wednesday.
P1 and P51 were both full... ... this was not good as i was rushing to make my flight...

but the nice people at europe-car took my big silver beast (aka range rover) parked it, washed it and got it back form me.

cost just over CHF120... for over 4 days parking, the wash and the convenience of it all. This seemed pretty close to the rate i'd have paid just for parking the car myself.

I'm not connected to europe-car in anyway, but i can recomend their valete paking service at geneva airport. http://www.gva.ch/en/desktopdefault.aspx/tabid-303/

Cheers

Bill