i hav exactly same car, i tried different things like removing the stock air feed with universal air filter but found i needed cold air feed pipe, i fitted the original back but just cleaned the stock panel filter, it seems to be pretty nippy above 3 thousand revs!
if u read the manaul i think the car is a 1245CC somethin like that so its almost a 1.25 basically.
the are nippy cars to be fair, i finding out also whether to create a cold air feed system where by takin out the panel filter and air box, fitting a cold air feed down to the bottom of the car running the pipes to a bigger air filter next to the engine, increasing air flow!
look up cold air flow for smooth intakes.
or you could rip out the engine and stick the sport engine in it?