Is this the shite that you just spray on to a hacky car and then wipe off (in!) all of the dirt etc?
It will scratch the fuck out of the paint, and surely you will need loads of cloths if the car is as manky as the Fiesta on the advert.
You will no doubt have scratched your bonnet from letting the bottle slide off too, but you won't notice it next to all the other swirling and scratching.
On a related note, me mam was telling me that some fella on their caravan site was made to pay the 'car washing' fee of about £2.50 for using that shit, I asked how/why considering there is no water!