Rip out the interior, swap the suspension over for some top end coilovers, mild exhaust, carbon fibre panels- lol... it'll never weight the same as an evo - it's a big car after all. Properly engineered supercharger kits are legal. You can even get them with a warranty from Walkinshaw Performance - if you have the coin. They have a kit where you can drive in with a brand spankers ss and drive out with around 480kw and over 800NM. Hard to argue with that.