
Physics buffs possible keep in mind Newton’s Third Regulation of Movement, which reads, “For each motion, there’s an equal and reverse response.”
And whereas Newton’s Third Regulation enjoys common acceptance as reality, you is likely to be asking your self the way it applies to automotive advertising and promoting. I’ll clarify…
Cadillac Seville Opera Coupe
All-New Seville
Cadillac launched the Seville for 1975. The brand new sedan was smaller, cleaner trying, and sportier than anything within the Caddy lineup. Promoting touted the new-think automobile as “European,” this given its tidy dimensions and high-tech options which included gas injection—uncommon within the mid-Seventies.

And for Cadillac consumers, the Seville’s showroom affect was profound. The brand new smaller Caddy, which was priced above different model fashions, was greater than two toes shorter than the favored Sedan DeVille, and weighed virtually 1200 kilos lower than the old-school mannequin.
However if you happen to thought that Cadillac was making progress updating and modernizing its automobile portfolio, you’d be flawed, as Newton’s Third Regulation of Movement kicked in with a vengeance.
Grandeur Motorcar Company
It’s doable the all-new Seville design regarded so clear and stylish, that it appeared to some as a clean canvas. One thing virtually unfinished. And whereas there was little most folk may or would do in regards to the new Caddy’s comparatively minimalist look, there was an organization in Florida that noticed the Seville as a block of clay simply ready to be molded…and gilded, and closely ornamented. That firm was the Grandeur Motorcar Company of Pompano Seaside, Florida.
Seville Opera Coupe
The Grandeur Motorcar Company was seemingly based to supply one automobile: The Cadillac Seville Opera Coupe. For an ungodly sum of cash, the Grandeur group would do issues to Caddy’s new premium experience that possible made manufacturing facility designers and engineers cringe. Right here’s an inventory of the modifications required to show a Seville right into a Seville Opera Coupe as pictured within the advert beneath:

- Shorten physique
- Shortened by 18 inches, rear seat and rear doorways eliminated
- Elongated hood
- Engine and firewall pushed rearward on body, creating longer hood, better distance from doorways to entrance axle, critically messing with proportions (The advert claims the Opera Coupe sports activities “mid-engine dealing with.” We’ve got our doubts.)
- Pretend side-mounted spare tire covers
- Chromey grille modifications
- Star Wire 30-spoke wheels
- Like them or not, they had been expensive
Costs
First provided on 1978 examples, the Opera Coupe conversion added roughly $6500 to the worth of a buyer’s Seville. That’s about $32,000 in 2026 {dollars} to spoil a superbly good Cadillac Seville.
Manufacturing
There are not any stable manufacturing figures available, however most estimates put the overall variety of Opera Coupes constructed between 1978 and 1979 at 600—a determine that, frankly, frightens this writer.
Lincoln Versailles
Grandeur additionally constructed a couple of related conversions of Lincoln’s compact Versailles, a automobile with a mission and market place just like that of the Seville. Additionally, there are footage of some conversions of next-generation “Bustleback” Sevilles (1980-1985), that are painful to have a look at. We are able to’t verify that any had been truly offered to the general public.
Energy and Efficiency
Unable to discover a assessment of the Opera Coupe, we are able to solely assume that it’s on-road efficiency was moderately Seville-like, regardless of the ill-considered modifications. That stated, the doorways, shortened as a part of the conversion, look very small for a luxurious automobile. Husky automobile collectors, take observe.
Collector Worth
The Seville Opera Coupe just isn’t particularly uncommon immediately, displaying up sometimes at auctions, and commanding what we consider are scandalous costs, given the commonly upsetting look of the truncated Caddies.
Current private-party gross sales of good-condition Opera Coupes put the worth the of the transformed Caddys between $15,000 and $25,000, which appear nuts to us.
Newton’s Third Regulation of Movement
However, again to Newton. Our level is that this: As Cadillac moved to replace and modernize its lineup, an equal pressure, from Florida, pushed again in opposition to the hassle, turning choose Sevilles into baroque caricatures of what most individuals keep in mind as basic vehicles.
If Newton had been right here to evaluate the state of affairs, one wonders if he would recognize the gravity of the matter.

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Cadillac Seville Opera Coupe Footage