Everyone knows that with the weight/dimensions/bulbous-ness (word?) and front wheel drive config of Devilles, any kind of spoiler on the back would be, at best, a "nod" towards esthetics. Some guys love 'em, alot hate 'em. Personally, I think that if they could come up with one that truly looked integrated ie; coming from the pen of one of GMs designers, one that blended in with the linear delineations of the rest of the arse end of the car, then it would be a big seller.
I remember waaaaaay back, around 1969, when Chrysler had a monster of a big car - Monaco Royale, or some such thing (not the Imperial, but close - certainly as big as one), and they had Hurst do one of his dress-up packages on it.
It was truly done tongue-in-cheek, 'cuz the Monaco was anything BUT a barn burning musclecar and it had the famous Hurst Gold paint stripe details, a goodly sized hood scoop (or two), and the most AMAZING spoiler on the arse end. It came up from the very end sides of the rear fenders and gracefully crossed over the trunk, back to the other fender. The whole thing measured maybe 2 1/2 inches or so high at it's centre. It was cool. Very, very, cool. The '69/70 Buick GS Stage 1 cars also had somewhat integrated spoilers and they were able to pull it off without looking silly.
And what made it look so damn cool on the Monaco was that it was fullyintegrated into the rest of the car - there was no way it could be mistaken for an add-on - or even worse, an afterthought. Even though it actually was both,,,,,,