dave said:
keep the stilo for family use an get a nice motorbike for fun
Yup, Dave is right. If you want to go REALLY fast, then buy a motorbike. 6K will get you a recent Fireblade or R1. Won't be able to fit your kids onto it though, so you'll have to keep the Stilo too
How do you fancy a real road rocket, that's fairly discreet, has hatchback versatility plus four wheel drive and a turbo?
Try a Nissan Sunny GTiR. Road tested in one magazine at 5.0 seconds 0 - 60, top speed in the high 140's, tremendous amounts of grip and the ability to leave most of the exotica/ supercars in the twisty bits. Plus you can still get all your shopping in the back along with three kids and a wife. Problem is they stopped making them in the early 90's.
A Sierra Cosworth is also worth considering, though unfortunately they seem to have been taken over by Chavs with too much money hence now have a boy racer image. Again, too old for you now and you don't like Fords.
Lancia Delta Integrale 4x4. Stonking performance, 4 doors and a hatch but too old. Same applies to the Audi Quattro Coupe.
Don't know what else to suggest really as I'm only into older cars...