DEAR CAR TALK: I am now the owner of a 1978 Cadillac Seville Grand Opera Coupe. This was my grandmother’s car and one of a few hundred made of this model.

It is not running, but I believe that is due to it sitting. It is all original and has very few miles.

What is the history of this model, and is it considered “desirable” or sought-after? Thank you! – Whitney

RAY: I don’t think anyone would ever describe this car as “desirable,” Whitney. Your grandmother either had very unusual taste (you might want to look for a picture of your grandfather), or she had a great sense of humor.

Or both. Because this is one of the weirdest, ugliest vehicles known to man.

For our other four readers, if you’ve never seen one, you owe it to yourself to Google “Cadillac Seville Grand Opera Coupe,” and then finish reading this column when you’ve stopped laughing.

This was not a car made at the factory by Cadillac, which reduces its value to some extent but also gives Cadillac plausible deniability for its existence.

The Grandeur Motor Car Company of – wait for it – Pompano Beach, Fla., made a bunch of these by taking a Cadillac Seville (which was based on a Chevy Nova), removing the front seats, extending the hood and windshield backward and having the driver pilot the car from where the back seat used to be.

But the piece de resistance – the touch that puts the Grand Opera Coupe in league with sky-blue polyester leisure suits and gold toilets – is the fake, wire-wheeled spare-tire covers that are built in, on each side, between where the driver sits and the front wheels.

Now, is there a market for these things, Whitney? Of course! I contacted our friend Craig Fitzgerald, who writes for bestride.com. He’s our go-to guy for all things automotive and ridiculous.

Craig said that since they are “conversions” and not original Cadillacs, even Grand Opera Coupes in great condition have never pulled in more than about $15,000.

He said that a Barrett-Jackson auction in Las Vegas got $16,000 for one in mint condition a couple of years ago, but I think they had to throw in a couple of Volkswagens with it.

Anyway, that’s something, Whitney, right? If you can get $15,000 or $16,000, you can get yourself something you might be willing to be seen in, like a 2015 Camry. Good luck.

Got a question about cars? Email Car Talk’s Ray Magliozzi by visiting the Car Talk website, www.cartalk.com.