Though not necessarily true to its original design, I have always loved Bernie Martinez's 1972 Alfa Romeo Berlina 2000. If PD were to ever have a premium Alfa Romeo Berlina they could just use Bernie's vintage racer as their basis for a Race Modification option.
I do enjoy the face of the TZ2 but its hindquarters ruin it for me. The GTA is a beautiful car and its simple design is something I appreciate more and more each time I see an example in person.