The targa topped 308 GTS was introduced in 1977 and was made famous on the television series Magnum, P.I.. Several cars were used, a new one for each season, most being auctioned off after filming.

Bosch K-Jetronic mechanical fuel injection was added for the 1980 308 GTBi and GTSi, dropping power to 214 hp (160 kW) but decreasing emissions. Two years later, the 4-valve per cylinder Quattrovalvole or QV model pushed output back up to 245 hp (179 kW) restoring the performance. The European version boasted higher horsepower than the American model due to lightness and less stringent Federalizing. Only 748 308 GTB QV models were produced, with one third being European models. The European 308 GTBi QV model is considered by many to be the most collectible 308 due to its subtle styling (deep front valance, racing mirrors, short lightweight bumpers) and speed as the fastest of all 308s produced.