Fuel pump, clutch failed, radiator leaks.
The dashboard cracked, may due to extrem hot dry summer as a friend of mine had the same problem with his S4 (1988). Other than that, everything was well thought on this car.
Its looks may be outdated, one may consider it as a classic and very representative of the 80's (which makes a head-turner). I find it handles more or less like my BMW 328. Nevertheless the later would not support 230km/h! That said, it is extremly fast.
I find it strange that you think that a 328 can't support 230kph, they can hit 250. Your 928 GT should be able to exceed 290 kph.