Make the question clearer:

If my mate was caught on a roundabout in a mx5 the wrong way what could she say so it doesn't go against her?

"I'm sorry"

That is a brilliant response haha! Thanks

Other than the TRUTH, there really is nothing to say as you are also under the legal driving age...

That's true.

If I was caught on a roundabout in a mx59 the wrong way what could I say so it doesn't go against me?

The big question is the "IF". From what I read into your post, it has not happened. So what is the problem?

If as in it has?

Driving against the flow of traffic is a serious business. Do so without a valid drivers license make it worse. Your only possible defense might be that the signs were misleading. So if this really happened, I would suspect getting a legal drivers license is not in your near future.

It was at nighttime and my mate just wanted to know

Nighttime is not an excuse. Actually it makes it worse, because he should have been able to see oncoming lights.

Okay thank you and just wondering because it was hailng and couldn't see anything, so my mate was just wondering how it would go down.

If driving conditions were that hazardous, then he should have pulled over and waited it out.

Okay thank you, will tell her.

I assume that other posts by OP suggest that (s)he was under age and without a license?

Oh, it would be here, post # 3. It seems that she is 16.

All the other qestions are mine, except this one was from my mate and she is 18 and she was just over worried.

Anyone who has to go to court needs to do 3 things that have little to do with 'what could I say.'
1. Show up early
2. Be well dressed as if for a business job, neat, and clean.
3. Stand straight with eyes on the judge and speak only when spoken to, answering only the questions asked. When the chance to apologize presents itself, apologize, with no excuses, (no one else was confused by signs), that you realize that you are inexperienced, and will strive to be careful and learn.

Okay thank you, will tell her.

@joy. You do realize this is in the UK, right ?

Yes why

Yeah why?