[Closed] Just had the police around, I've been accused of racism

I had an altercation tonight in a supermarket car park. My wife, youngest daughter and I pulled in to the car park (all the family spaces were taken), parked and walked towards the shop when a youngish guy came out of the supermarket, jumped in his car parked in a family space and started to drive off. I shouldn't have done it, but I had a bit of a go about him parking in a family space, he wound down his window and we had further words, which resulted in me calling him a prick. He had a go back and he suggested we fight and more words were exchanged before I walked away and forgot about it all after taking a bit of a bollocking from my wife.

About three hours later the doorbell goes and I answer the door to two police officers asking if the Volvo car outside was mine, I confirmed it was and then he asked if I had been in an altercation in a supermarket car park. It actually took me a while to register what they were taking about, as it was essentially handbags at dawn before he asked if I remembered what I said to the person in the car. It then registered that the person I argued with wasn't 'white British' origin, and a horrible realisation dawned on me, I was being accused of using a racist insult.

Thank goodness my wife (who heard the whole thing) backed up my assertions that I would never used racist language and the police seemed pretty satisfied that the report was a petty way of getting back at me.

I'm devastated, not only at the accusation of racism, but the police turned up in front of my two young kids and I had to explain what they were accusing their dad of. I'm angry and hurt, I wish I had kept my mouth shit initially but I feel I shouldn't let this bloke get away with absolutely untrue accusations of racism, do I have any grounds for slander with my wife being witness?