I have heard that the BMW M5 is capable of topping 190MPH easily without limiter. Remember, it has about 500BHP out of the crate!
They used it for the Blind speed record (which was a very dull thing to watch on a TV show, cant remember which one)
That said, I once had a run in with a Lotus Carlton in Bristol. I will never forget it, the guy had painted it RED (yuk!). I remember sitting beside him at lights claiming to my mate that it wasnt real cos they never made them that colour, and then proceeded to have my arse handed to me by him!! DOH!
Stunningly quick car, but couldnt go round bends!
JJ