Under the new body the 508 C had more modern and refined mechanicals compared to the 508, including independent front suspension and an enlarged overhead valve engine.

[6] Unusual for a modestly priced car of the time was the independent front suspension, while the rear had a leaf sprung live axle.

The lengthened 508 L also formed the base for two light commercial vehicles, a van (Italian name 508 L Furgoncino) and a platform lorry (508 L Camioncino).

The car had gained a taller, pointed grille—which earned it the popular nickname of 1100 musone,[7] i. e. "big muzzle"—with horizontal chrome bars, the top three extending back over window-shaped louvres on each side of the redesigned engine bonnet.

The revised type 1100 B engine produced 35 PS (26 kW) at 4,400 rpm[8][4] thanks to improved inlet and exhaust manifolds and a larger 32 mm diameter choke carburettor.

At the end of the summer of 1949, the car was re-introduced with a curvy, exterior boot, a column shifter, and a new name: 1100 E. A longer wheelbase, EL model was also available, although only for taxi use after 1950.

The novel coupé body had a peculiar but highly aerodynamic shape, characterised by a flat, elongated roofline, an abruptly cut off tail, and some very modern traits like an uninterrupted fender line and smooth sides—a first on a Fiat.

[10] As the Mille Miglia model was developed mainly to help promote the new 508 C by competing in motor racing, the chassis had to be carried over from the saloon and couldn't be lowered or altered to reduce the frontal area.

[11] According to Giacosa inspiration for the sports coupé's body came from observing that during test runs a prototype 500 Topolino-based van could reach a higher top speed than the saloon it was based on.