This rebuilding process brought some better looking body's like the 99' GT (bottom of page). With the 90's the fuel economy came back up to full speed, and also brought bigger engines. 

Through the 90's Ford was also being more Millennium oriented. Ford wanted to give the Mustang a whole new look for the new Millennium, and they did a good job of waiting for it to come. In 1998 Ford unveiled the 99' Mustang GT the 99' Mustang brought back the muscular body of the 70's. 

It looked not only mean but evil sitting still, let alone roaring past you spitting rocks and gravel at you. It also came with a great  engine improvements like the 3.8 Liter V-8 with 190hp, and the 4.6 Liter V-8 rating at 260hp.