I personally don't use them on my car (I do on anyone elses or the work van though ) I'm always concerned they'll scratch.

I use a lambswool mitt, Poorboys shampoo and Poorboys waffle towel thingy! IMO Autoglym synthetic chammys are still the easiest option but the waffle towel, again, prevents swirls/scratches.

For any advice I would advise a chat with Gareth (of detailed obsession) I spent hundreds of pounds with him last May on bufty stuff along with a Porter Cable but I still haven't had time to use it!! Top bloke though.