Any advice on how to remove swirl marks?

 

Get the Harley swirl remover polish or an equivalent. Follow the directions carefully. Apply plenty of elbow grease. Repeat process as needed. Then apply regular wax. Voila!!!!

 

The best protection for your paint against U.V. rays as well as the best restorative product that I have ever used is "Auto glym". It cost's a few bucks but it brought my 20 year old black paint on my Electra glide to new looking. You only need it once a year although I hit it more often.
I had swirl marks & years of little scratch lines. Most of them are gone.