Bluesmobile Mark 1

[tigercat]

Everyone thinks of the Bluesmobile as the ex Mount Prospect police car but that is Bluesmobile 2 . So their is scope for Whiffing the original Bluesmobile .

[scooter]

Everyone thinks of the Bluesmobile as the ex Mount Prospect police car but that is Bluesmobile 2 . So their is scope for Whiffing the original Bluesmobile .

Which, according to the dialog, was a Caddy that Elwood traded for a mic.

[Jake and Elwood are arguing about the new Bluesmobile]
Jake: What is this?
Elwood: What's what?
Jake: (pause) This car. This stupid car. Where's the Cadillac? (Throws cigarette lighter out the window) The Caddy, where's the Caddy?
Elwood The what?
Jake: The Cadillac we used to have! The Bluesmobile!
Elwood Traded it.
Jake: You traded the Bluesmobile for this peice of poo-poo?
Elwood: No ... for a microphone.
Jake: A microphone? [Pause] Okay, I can see that. But what the hell is this?
Elwood: I picked it up at the Mount Prospect police auction last spring. It's an old Mount Prospect police car. They were practically giving them away.
Jake: Well thank you, pal. The day I get out of prison, my own brother comes to pick me up in a police car.
Elwood You don't like it?
Jake (Very long pause) No, I don't like it.

That, of course, begs the question then of "What kind of Caddy?"  I tend to lean towards something with the aerodynamics of a strip mall, and the gas mileage to match.

[tigercat]

Such as ....

https://en.wikipedia.org/wiki/Cadillac_Gage_Commando

[Rick Lowe]

Such as ....

https://en.wikipedia.org/wiki/Cadillac_Gage_Commando

[Nick]

That, of course, begs the question then of "What kind of Caddy?"  I tend to lean towards something with the aerodynamics of a strip mall, and the gas mileage to match.

That makes me think of Boss Hogg and his bull horn adorned Cadillac. 

Reading up on it, it turns out that Jake and Elwood had a 1968 Cadillac Fleetwood https://en.wikipedia.org/wiki/Cadillac_Sixty_Special#1965%E2%80%931970

[McColm]

Something along the lines of the Ghost Busters Caddy.

[zenrat]

Something along the lines of the Ghost Busters Caddy.

Not quite.
The Ectomobile, or Ecto-1 is a 1959 Cadillac Miller-Meteor Futura Duplex limo-style endloader combination car (ambulance conversion).
https://en.wikipedia.org/wiki/Ectomobile