The original 'frogeye' Sprite had been introduced specifically to fill the gap in the market left by the end of production of the MG T-type Midget as its replacement, the MGA had been a significantly larger and more expensive car with greater performance.

[4] Mechanically the car was identical to its Austin-Healey counterpart, retaining the rear suspension using quarter-elliptic leaf springs and trailing arms from the 'frogeye'.

In late 1967 (1968 model year), US-spec cars received several safety additions: a padded fascia (dashboard) with smaller main gauges, collapsible steering column, scissor-type hood hinges, a third windshield wiper, additional side marker lights, and anti-burst door latches.

The 13-inch Rubery Owen "Rostyle" wheels were standardized, but wire-spoked ones remained an option, fitted with either 5.20x13 Crossply tyres or 145HR13 Pirelli Cinturato CA67.

These revised cars were initially presented with a matte-black-painted windscreen surround which proved so unpopular, the Midget reverted to the original brushed alloy after only a few hundred had been manufactured.

The round-arch Midgets with chrome bumpers marketed for model years 1972-1974 started leaving the Abingdon factory in late 1971.

[5]To meet US federal regulations, large black plastic-covered bumpers were added to the front and rear and the ride heights were increased.

The increased ride height affected handling and anti-roll bars were added to help with the higher centre of gravity.

Although the horsepower ratings were similar at 65 hp (48 kW) in home market specifications with twin SU HS4 carbs, the 1493 cc engine produced more torque.

The increased output combined with taller gear ratios resulted in faster acceleration (12 seconds 0–60 compared to 13 for the 1275 cc version) and top speed of just over 100 mph.

ADO34 was the name of a project active between 1960 and 1964 that aimed to develop a front-wheel drive Mini-based roadster as a possible new MG Midget or Austin-Healey Sprite.

MG racing driver and garage owner Dick Jacobs persuaded Abingdon to build a pair of special lightweight Midgets with a GT body shape inspired by the Aston Martin DB4.

The two loaned to Dick Jacobs were originally fitted with 979 cc A-series engines with twin Webers and approximately 80 hp (60 kW).

They were fitted with 18.5-imperial-gallon (84 L) fuel tanks, larger oil coolers, large-bore exhaust systems and dual-circuit brakes.

Many in the U.S. consider the 1967 model year to exhibit the best stock performance; the 1275 cc engine was unencumbered by power-sapping smog equipment and the added weight of later giant bumpers.