Despite yours and others constant childish comments about me and my business, here is my honest advice as someone who has been to court relating to my window cleaning business:
As previously said, wear a suit. Buy one if you have to and here is why: Use this opportunity as an advert for your business. Look professional, sound professional. Dress and groom like its a posh wedding. You are entering one of her Majesty's establishments. You don't know who will be in the room, so IF POSSIBLE AND APPROPRIATE, mention the name of your company. The least you should say is that 'As a local businessman, I am here because I feel it is important that things are done honestly and justly. My clients depend on my being trustworthy. That's why I left my business card with the lady' You may even be asked the nature of your business next, you never know. Look for the opportunity. I would, as you know. But thats me.
As for not wanting a day off work, get your accountant to write the insurance company and court a letter highlighting your loss of earnings for attending the hearing. The accountant will look at your total income for the last tax year and divide it by 260. That's your average amount earned during a day. It will form part of the claim for the lady you are representing. You will get paid by her insurers and they claim the money back from the other insurance company.
For the record, I only speak on here when I feel I have something unique to add. There are shed loads of window cleaners offering good advice. That's why I rarely 'contribute to the forum' as people say, in a way other than I do. This has not been flooded with answers, but I have experience I am happy to impart.
I am not as many, including yourself, paint me to be.