The final Mondial evolution was 1989's Mondial t (Coupe and Cabriolet). It was a substantially changed model, "spearhead of a new generation of V8 Ferraris", according to Road & Track

Road & Track

Road & Track is an American automotive enthusiast magazine. It is owned by Hearst Magazines, and is published monthly. The editorial offices are located in Newport Beach, California.-History:...

magazine. It was visually different from preceding Mondial models, the most recognisable being the redesign of the air intakes to a smaller, neater rectangular shape. The door-handles were of a visually different design and, along with the bumpers, became body coloured, whilst a painted black band was added around the bottom of the body.
The 't' called attention to the car's new engine/transmission layout: the previously-transverse engine was now mounted longitudinal

Longitudinal engine

In automotive engineering, a longitudinal engine is an internal combustion engine in which the crankshaft is oriented along the long axis of the vehicle, front to back....

ly whilst the gearbox remained transverse, thus forming a 't'.