A few spoilers here...
Director Richard Thorpe had earlier directed Elvis in 1957's "Jailhouse Rock," the young singer's third film. "Jailhouse Rock," shot in black and white, featured a somewhat dark atmosphere and a far-from-benign Elvis. "Fun In Acapulco" is different fare all together. Elvis's figurative (and temporary) emasculation by the Hollywood machine is obvious in most of his '60s 'travelogue' musicals and this film presents the sanitized Elvis in his full glory, lacquered hair and all. The story's fairly typical in its lightweight nature -- Elvis films of the '60s were generally nothing that you'd confuse with something written by Eugene O'Neill -- but it has a couple of twists and a bit of a backstory.
The basics are that Elvis finds himself unemployed in Acapulco, short on money and too short on time to secure a work permit. He hooks up with a young street kid, Raoul, who's basically a pint-sized Colonel Parker (Parker, for the uninitiated, was the huckster who was Elvis' manager and who became as much a legend among managers as Elvis did among performers), always on the make for new ways to turn a peso. Elvis ends up doing double-duty as a lifeguard and as a fill-in singer at various clubs after Raoul helps him get his first gig at the Acapulco Hilton (the Hilton name to become more intimately associated with Elvis' name in the '70s when he changed the face of Vegas). Elvis experiences 'double trouble' yet again, being pursued by and pursuing two bodacious babes (a famous lady bullfighter, played by Elsa Cardenas, and the Hilton's Assistant Social Director, played by Ursula Andress), in the process ticking off the local diving champion (Alejandro Rey, who played the Cuban immigration lawyer in 1984's "Moscow On The Hudson"). Said rival reveals the fact of Elvis' character's past -- that he was a member of a family-based circus-acrobat team who 'lost his nerve' when he let his brother fall to his death.
I picked up on a few ironies within the film, some of them probably planned and others retrospective ones that were obviously not. Among the first group were Elvis talking about somebody being "all shook up" (actually, I think I've seen that one in another of his '60s films...maybe "GI Blues"). Elvis also talks about kings having had food-tasters, and follows it up with another mention of 'the King' (not, by the way, a title that Elvis was overly fond of when applied to himself). The other kind included Elvis donning a bullfighter's cape for part of a song, as a kind of visual premonition of his stage suits a decade later, and Elvis shocked that his young 'manager' expected a hefty 50% of Elvis' earning (exactly four years after this film was shot, Colonel Parker renegotiated his contract with a recently-concussed Elvis and claimed a whopping -- and undeserved -- 50% of Elvis' income along with other concessions that effectively gave the wily old carny more Elvis-derived funding than Elvis himself received).
Interestingly, Elvis didn't go south of the border for this film -- all of his wide-angle and long-shot scenes in which Acapulco scenery is evident were shot using doubles. Most of the back-projection composites are really well done, too, to the point that some people have a hard time believing that he wasn't in Acapulco for at least part of the shoot. Apparently, Colonel Parker reminded Producer Hal Wallis of the nightmare that filming became in New Orleans while working on the 1958 classic, "King Creole," and raised the specter of being forced to rely upon a few local policemen in a country where the principals didn't know the ground rules nor the relevant agencies. Elvis made up for the deficit by taking Spanish tutorials to try to improve his pronunciation (Ursula Andress, in the meantime, was trying to improve her English).
The Mexican flavor of the film is tastefully done and is consistent and authentic. It was really a natural combination. Elvis had always -- since the '50s -- incorporated some Spanish and Mexican stylings into his dress (as he continued to throughout the '60s and even more obviously in some of his rather jawdropping '70s on- and off-stage ensembles) and the same is true of his music. Although Elvis' prime influences were black and white gospel traditions, blues, country, and Dean-Martin-style pop balladeering, many of his '60s and '70s songs have an obvious Spanish tinge. In the 1970 documentary, "Elvis - That's The Way It Is," Xavier Cugat states for the camera that Elvis "sings Spanish songs like nobody."
I like this film. It's not a great film, and it's not even the best of Elvis' '60s musicals, but it's enjoyable and pleasant and is far above many of the films that followed, particularly those shot 1965-67. A harmless diversion, you might say, and both Elvis and his female co-stars look great. The soundtrack, though, is one of my favorite of Elvis' movie years. Elvis really nails the Mexican sound, probably thanks in part to the backing efforts of the LA-based Amigos. Most of the songs are presented well, too, and most are presented in natural settings and well shot. Check out the tasty little number, "Bossa Nova baby," and witness Elvis' ability to move upper and lower halves entirely independently. Pretty good workout. The ending "Guadalajara" is great, and Elvis delivered the take used in the movie after only a couple of attempts in the studio, having learned the lyrics phonetically. "No Room To Rhumba In A Sports car" is the weakest song, but even it has a certain charm. By the way, the Beatles saw this movie at a Florida drive-in during their first US tour (they were hoping to have seen Elvis in person but had to settle for the celluloid version until their next tour of the US).