Upon release, the Rialto had a 12-month waiting list in 1982, and was one of Reliant's best-selling models ever, but never gained as much praise[citation needed] as the better-known Robin.

The idea of updating the Robin dates back to 1978, but by 1980 sales were slowing, and Reliant thought a simple facelift may have fixed this.

In the end Reliant decided to save money by continuing to use the mechanical parts of the Mk 1 Robin, such as its running gear, but update the whole car with a new style of body, and rename it the Rialto.

GLS specification cars which came with a clock, FM/AM radio, voltage gauge, cloth covered seats with extra matching cloth covered areas on the interior, extra thick carpets with a carpeted boot area, GLS decals, leather steering wheel, a spare wheel, and radial tyres.

This engine was carried over from the previous Mk 1 Robin, and produced 40 hp (30 kW), a top speed of 85 mph (137 km/h), and fuel consumption of up to 60 mpg (imp).

The most recognisable feature of a Mk 1 Rialto is the thick stripe which runs front to rear, in either gold, graphite, or silver –according to body colour.

By late 1984, the Rialto 2 was re-released with an altered specification; the rear axle ratio was returned to 3.23/1, as customers complained of being unable to use 4th gear at city speeds, and the economy gauge was no longer fitted.

Mechanical parts of the new Rialto SE had reverted to the standard specification engine, but now with a grey rocker cover, and were equipped with a pre-engaged starter motor for improved starting.

In 1997 the Rialto SE received the same improvements as the new Robin: it gained 12-inch wheels, a new braking system, different interior trim, and an updated dashboard design with new dials.

The first television ad for Chrysler's revived Dodge Dart also features a scene referencing the notorious reputation of Reliant three-wheelers.