This ^^dont buy a car if you not happy with the performance, going from a 200hp light fiesta hatch to a heavy 2ltr coupe was never going to be a huge impact really just because its a well handling rwd car.
admittingly my first finance car when i was 20 i did alter, but aftermarket audio system, cone filter, 17" alloys within the first couple years of a 4yr contract, but i managed to pay off the car before the end so was no problem.