'kin 'ell Rusty - she's a game old lass isn't she?
No cats would make a difference, clearly, though the biggest engineering challenge is getting gasses in in sufficient volume to create the horsepower required, rather than evacuating them.
The law of deminishing returns certainly comes into effect when pushing roadcars, however exotic, to the limit. I think it's entirely possible - even with a stock car, if the conditions are perfect. We all notice that our motors run better when it's cold and damp - though hardly ideal conditions for a 200mph+ honk on a public road.
Aside from the obvious minor dramas, like, say a pissed-blind farmer driving his tractor out in front of you, I would have sneaking concerns about the tyres being able to stay together - even Y rated, as fitted to the Diablo. Scary stuff - hat's off to the lunatic!