Right, update on the Farecla clay mitt. Very easy to use, but you MUST lubricate heavily. If you don't bits of the 'clay' substance on the mitt will transfer across onto the paint and then it's quite an effort to get it off. I'd say overlubricate if you want to keep the mitt in best condition, but it's the easiest 'claying' I've ever done. Paint feels glass smooth, and despite the S5 having a large surface area it only took about 30 minutes to do the whole car including windows. For the money & ease it's a no brainer unless you're on of the purist detailer breed!