[GusGecko]

Swirl marks are generally caused by poor washing (of course there's many other ways too)

The only way to truly get rid of them is by machine polishing. (Easy to do if your prepared to buy a DA polisher, pads and products)

However you can certainly mask/reduce the effect through both retail products from somewhere like Halfords by hand and of course more specialist products.

Look for polishes and scratch remover products. Alternatively a glaze is a filler which will mask the damage for a period of time.

If you some any polishing or glazing, be sure to protect with a wax or sealant :-)