how much did that cost you if you don't mind me asking?
Get the sponge out some icy cold water a hose and rub it dry pour the contents of a washing up bottle on roof hose down car and rub
works fine also leaves your hands nicely numb
or pay someone to do it 15 quid at petrol station inside and out
1 that fits a Karcher is £49 befor discount in the members offers section
and the Gilmour Foamaster II for other washers is also £49 before discount
if you beg him he chucks in a bottle of snow foam too
https://www.fiatforum.com/member-offers/
Gilmour gun is only for hose use