Thanks guys - I haven't been this happy with something since I was a kid.
It was Decently Exposed that did the work for me. Also known as AutoSkin. They normally do full wraps and that sort of thing. They did the local mini dealerships minis as it turns out.
They even replicated the artwork on little model minis for them. Sadly I couldn't find a decent pure silver mini model and it was a bit much.
Hmm, I do need to show to one of these mini drives don't I! The missus is away for a month now so this is a prime opportunity