FAQ

The real life detective on whom the character was based on was nicknamed this as he was constantly looking around for crime and suspects, hence "pop-eye".

The word "frog" is often used as a derogatory term for someone of French descent. When Popeye refers to Charnier as "Frog One," he's trying to distinguish Charnier from his partner, Pierre Nicoli. It can also be a way to show Popeye's generally bigoted attitude. Earlier in the story, Popeye uses the N-word while talking to Cloudy about Willie having slashed him with a knife while they were arresting him.

He's deliberately trying to confuse Willy into making a confession. Poughkeepsie is a small city about 80 miles north of New York on the Hudson River. Willy may have a drug connection up there that buys product from him and sells it in that region. His line, which is somewhere along the lines of "When was the last time you picked your feet in Poughkeepsie?" is basically nonsense. Repeating it and variations of it including only Poughkeepsie or just when the person has last "picked their feet", over and over in a threatening manner, is a tactic meant to bewilder the subject. While the criminal is desperately trying to figure out what this sentence is a code for, the interrogators intersperse the badgering with actual questions like "Who's your connection Willie, what's his name!?" and "Is it Joe the barber?" Willie, already terrified, beaten and totally confused, doesn't know what this Poughkeepsie thing is, but it sounds bad and he surely didn't do it. So to take the questioning away from this mysterious act the police think he's performed must be pretty terrible, so Willie admits to what they really want to know out of fear. This tactic/phrase was actually developed by the character that Gene Hackman played in real life (the movie is loosely based on a true story). Source: French Connection Commentary extra found in the DVD version of the movie.

The scene came about after director William Friedkin was told by a head mechanic (Irving Abrahams) that his police garage was so well equipped it could disassemble and reassemble a car in 4 hours. So yes, we're supposed to believe that after half an hour or more of tearing the car apart, they spent several hours putting the same car back together. Irving Abrahams in fact got a role as a mechanic in the film.

However, since they dramatized damaging the interior & trim as they tore the car apart, we have to assume they sourced another Lincoln for replacement parts at the very least, if not as a whole new car. It helps that in the film the garage claims they have hundreds of cars coming in per day. If they did provide Devereaux with a replacement car, they'd not only have to stash the heroin under the rocker panels and transfer the license plates, but switch the ignition and door lock cylinders as well. French cars also have speedometers and odometers in km/h and km rather than mph and miles, and had yellow headlights at the time. If they managed all this then it adds a note of humor to the story, when we see Cloudy take Devereaux to "his" car.