Difference between Roadster and Runabout

ROADSTER vs RUNABOUT: NOUN

A small lightweight carriage; drawn by a single horse
An often roofless or convertible automobile having a single seat in the front for two or three people and a rumble seat or luggage compartment in the back.
A sports car.
A horse driven or ridden on the road, used in driving for pleasure and for light work rather than for draft.
A person much accustomed to driving; a coach-driver.
In hunting, one who keeps to the road instead of riding across country.
A tricycle or bicycle built strongly for road use, as distinguished from one intended for racing.
Nautical, a vessel which works by tides, and seeks some known road to await turn of tide and change of wind. Also roader. Admiral Smyth.
A clumsy vessel that works its way from one anchorage to another by means of the tides.
A horse that is accustomed to traveling on the high road, or is suitable for use on ordinary roads.
A bicycle or tricycle adapted for common roads rather than for the racing track.
One who drives much; a coach driver.
A hunter who keeps to the roads instead of following the hounds across country.
A sea-going vessel riding at anchor in a road or bay.
An open automobile having a front seat and a rumble seat
A classic style of bicycle, usually steel-framed.
A person who lives along the road.
A horse for riding on the road.

An open automobile having a front seat and a rumble seat
A small motorboat.
A light aircraft.
A small, open automobile or carriage.
A vagabond or wanderer.
A gadabout; a vagabond.
Any light open wagon for ready and handy use.
A small, light-weight, open motor-car, or one fitted with a buggy-top, designed to carry two persons, and intended to operate in towns or cities or within short distances; also a small motor-boat.
One of a herd of cattle left to run about and graze at will.
Any of several small vehicles, especially a small motor car for use on short journeys.
A motor car having a single row of seats (Wikipedia).

Tourer, Miata, Hatchback, Fastback, Sedan, Drophead, Ragtop, Hardtop, Cabriolet, Cut, Trip, Coupe, Two seater, Buggy, Runabout

Sedan, Yacht, Tourer, Dinghy, Outboard motor, Sailboat, Speedboat, Catamaran, Cabin cruiser, Motorboat, Powerboat, Boat, Oldsmobile, Two seater, Roadster

Wankel engine, Notchback, Tourer, Miata, Hatchback, Fastback, Sedan, Ragtop, Hardtop, Cabriolet, Cut, Trip, Coupe, Buggy, Runabout

Skiff, Sedan, Yacht, Tourer, Dinghy, Outboard motor, Sailboat, Speedboat, Catamaran, Cabin cruiser, Motorboat, Powerboat, Boat, Oldsmobile, Roadster

ROADSTER Next floor, sundries, knick knacks, escaped convicts.
Toon roadster that ROARS out of the gates.
Norton Commando Roadster Fuel Tank in raw steel.
Malvern Star roadster frame that can do this.
Audi TT Roadster Top with Heated Rear Glas.
She took him in her roadster to a picnic supper, and after supper she disappeared, likewise in her roadster, with another man.
While attending the 2006 Grand National Roadster Show she was invited to bring her '32 Roadster and show a short documentary film she shot.
The 1930 Chevrolet Roadster Truck was Chevrolet's term for the two-seat roadster body with a pickup bed.
The control system in the new Audi TT Roadster and TTS Roadster is fully focused on the driver.
The 2010 Can-Am Spyder roadster line-up includes the Spyder RS (roadster sport) and Spyder RT (roadster touring) models.