Dialect Fail In Books - Your Help?

Something I've been meaning to ask you: could you help me in finding material for a talk I'll be doing soon?

I'm giving a talk called Whose Language Is It Anyway? at the first Brighton Book Festival ("Bookstock") on 9 June (click the Whose... link for details). Since it's a book festival, I'd like talk about some books. So I'm looking for examples of dialogue, first-person narration or anything, really, in which the dialectal features of the character are not right.  Really what I want are examples of US authors getting UK dialects wrong or UK authors getting US dialects wrong...but things from other anglophone countries might be helpful too.

(What I don't need is film dialogue or film accents, thanks!)

So, has any bad dialect representation stuck in your head? It'd be really helpful if you could provide author and title info with the examples. And if you read anything relevant before the 9th (or after, even), I'd love to hear about it.

And, of course, there is the possibility that some examples may be intentional.  When a UK book is published in the US, for instance, some unfamiliar words might be changed for the US audience (as famously happened for Harry Potter--warning there are a lot of errors at the link. Part way through the list, they seem to have reversed 'US' and 'UK').  It must happen in the other in the other direction too--so if you'd like to point any of those out, I'd be grateful. (The one I can think of is that Melanie Gerth's children's book Ten Little Ladybugs is Ten Little Ladybirds in the UK--and from what I can tell on the internets, the book is originally American.  And that tells you all you need to know about why I need help finding books. I haven't had time to read a novel since maternity leave. I look forward to reading my next one in retirement.)

So, have you got/do you have any examples for me? I'd love your help...