Origin of the term "Spyder"
 

Does anyone have a history of the term "Spyder" as applied to convertible sports cars?
Thank you,
Kevin

"As with other automotive terms, the term derives from horse-drawn carriages. A "spider" was a lighter version of a phaeton, having narrower, spindly wheels and two-seat accommodation. The name implied an extremely rudimentary top mechanism originating from a small two-seat horse-cart with a folding sunshade made of four bows; with its black cloth top and exposed sides for air circulation it resembled an eight-legged spider. This term was subsequently applied to automobiles. "

Spyder
 

Thank you for the background and history lesson. By any chance, do you know why and when the i was changed to a y when used for an automobile?

In the past, Ferrari used the spelling "spyder". Now, they're using "spider". Lamborghini continues to use "spyder".

From Wikipedia:

GTS ("Gran Turismo Spyder") in older models, are open Spyders (spelt "y"), or convertibles (see 365 GTS/4); however, in more recent models, this suffix is used for targa top models (see Dino 246 GTS, and F355 GTS; the exception being the 348 TS, which is the only targa named differently). The convertible models now use the suffix "Spider" (spelt "i") (see F355 Spider, and 360 Spider).

Seems like a marketing preference to me, but not really sure.

Car body style - Wikipedia, the free encyclopedia

Yeppers.

In addition to the above, a spyder had two wheels like a racing sulky, only big wheels that would roll better over ruts or bumps. Lighter, quicker and faster than a carriage, but capable of transporting a man and a lady. If you find any contemporary illustrations, they will sometimes show them racing on public roads.

It's purely a style choice on the part of the company - it has no significance. The two have been used concurrently throughout automotive history.

Just to add (someone correct me if I'm wrong), a "Cabriolet" or "Cab" was a horse-drawn, opened topped taxi.