hello steve, welcome to the club!
twingo gt's are fantastic little cars in just about every way possible. 100bhp means it's a dam site faster on it's toes than any other 1.2 car out there, and having a turbo means that you can remap it (one has gone upto over 200 bhp, i know right!? mental). they are very reliable too, the TCe engine is fantastic. really sturdy, never skips a beat. the car is also cheap to buy and maintain, holds it's value really well!
very easy to modify so that the car ends up exactly how you want it, looks and performance wise.
look out for brown residue around the spark plug leads, this usually indicates the scuttle panel is leaking. that was just about the only known fault with the GT! i've owned my GT for 3 years and the only things to have gone wrong with it was a wheel bearing and a stuck spark plug, my fault and not the cars fault!!! can't say fairer than that