Ford ka, because you're a woman.
Is yours purple like 99% of them on the road.
Seriously mate just don't bother, your mates will see you in a ford ka, laugh at you, see you speed off probably not notice the difference and call you a chav while still laughing.
You could do a chav makeover induction kit and zorst off ebay, ebay resistor, ebay smoked tail lights, ebay chrome gearknob and a personal plate, from ebay.
Modding is great provided you mod something worth it and use quality bits i reckon.
Get something decent before you turn it into something better, you can't polish a turd.
And being 17 you won't be able to insure the turd.