Clay bar will not remove swirls in the lacquer coat. It will only remove deposits, not scratches.

I'm going to have to use one on the MX-5. My daughter has moved to a house with a damn great tree overhanging the parking spaces. I make sure my car isn't here at dusk when the incontinent pigeons roost but I forgot about tree sap. One proper polish and two goes with waterless carwash have not removed it and it feels like fine sandpaper.

Of course claying might indirectly reduce swirls by reducing the amount of rubbing needed when washing.

I use noodle mitts rather than sponges, and two buckets - one to rinse the mitt and the other with the suds in. I still have swirls and lots of them.

The longer you keep off the paintwork with anything- sponges, cloths, leathers, polishes, the better for the finish.

I use a pressure washer and put truck wash through it, which dilutes it and makes a soapy foam, let the foam sit on the bodywork for a few minutes, then jet wash it off at a lowish pressure. Then mix up some Demon Shine and put that through the jet washer all over the car, that beads the water, and follow that up with an electric leaf blower to blow the water off.

A shiny car and you haven't actually touched it!