In the recent episode where they go to Bora Bora. Bruce, Kim, Scott and Kris Jenner (the mom) are all sitting at a table and Kim and Kris get into a playful argument.
Bruce: she used to have her hair slicked back when I first met her, she had the Elvis look.
Kim: now she's as fat as Elvis, in his last year.
Bruce, lol, oh, oh oh!!
Kris: well maybe I'll get a white jumpsuit then? Will that make you happy?
Kim: gives her a funny look like "maybe".
While it wasn't really positive it's still publicity on the biggest reality show on television. However, Kim has tweeted before that she thinks Elvis was gorgeous so it might have just been for tv. I have heard some of the show is scripted for tv.
On the spinoff show of KUWTK called
Kim And Kourtney Take New York, they go to Vegas for Kim's 30th birthday party and Kourtney yells out "woohoo, viva Las Vegas baby!"
And Khloe has made a reference to Shake, Rattle and Roll, which is a popular song by Elvis.