sure I read in one of the motoring rags about Vauxhall intending to sell a 225hp version of their 1.9d now that could be usefull in a 21 Exteme....BM were also doing simular power with around 2ltr!!!
but what ye really need is 650hp from the 5.5ltr v10 le mans dti winner, now that would be kicking in a 21 Exreme, of course you would also require an XR3 spoiler as well on the rear deck