Other mistake: When Kevin and Perry go home to find the postman at the front door, the postman asks Kevin to sign for a letter (his father's). If you look closely at the address on the postman's sheet it does not match the address on the letter. You need to be quick and look closely.
Continuity mistake: When Kevin and Perry are DJing in Kevin's room, there is a green lava lamp in front of the decks. In one shot the lava lamp is switched off, and in the next shot the lava lamp is switched on, and in the next shot it is switched back off again. (00:21:05)
Continuity mistake: When Kevin is arguing about going to Ibiza with his dad you can see sometimes in the background Kevin's mum is holding a glass and sometimes she isn't.
Continuity mistake: When the two are lying down on the beach because of their stiffies they get hooked in, so start pulling towards the sea the camcorder Perry dropped isn't by him in some of the shots.
Revealing mistake: At "El Beachio," when Kevin and Perry order the two lovely ladies a drink, you can briefly see that the glasses are already nearly empty as the waiter gives them to the girls. Presumably, this was done because the girls are expected to nearly finish their drink in a couple of seconds before making a sharp exit due to the embarrassing fake phone call Candice just made. (00:27:35)
Continuity mistake: When Eyeball Paul puts their footage from the video camera up on the screen, whilst their song "All I Want To Do Is Do It" is playing in the night club, on the video the way Kevin says "Candice, lick my candy" differs from when he said it into the camera earlier in the film.
Revealing mistake: When the two are in the mall at the beginning walking towards the camera you can see a couple of people in the background watching the filming.
Continuity mistake: At the beginning we see Kevin throw a book on the floor and it lands leaning against the wall. Later just before the end of the scene the book is gone.
Revealing mistake: When Kevin and Perry get puked on in the nightclub by the first guy on the balcony, you can see the second guy with his hands round his mouth covering the equipment used to project the 'sick' for a few seconds before he pukes. (01:05:00)
Answer: In the UK, at the time of filming the Ford Focus was a very popular family car. Not sure if it was the most popular but its definately a stereotypical family car. So its use would have been to signify that Kev's street is in a typical suburban area.