Visible crew/equipment: In the last scene, seconds before the end, just as the two Beetles drive off together, you can make out a driver, dressed in black, in the new Beetle, whereas you are led to believe the vehicle is driving itself. (01:30:40)
Continuity mistake: Look at the dirt when Herbie backs away from the nose of the newer Beetle, between the races out in the desert. Although Herbie drove straight up to the newer Beetle, tire marks can be seen where the crew moved the car back and forth to get him lined up.
Continuity mistake: When Maggie goes to look at the green Nissan 200SX, it has a set of standard Nissan alloy wheels. When the shot cuts to Herbie being lifted above the Nissan, the wheels have now changed to standard steel wheels.
Continuity mistake: At Crazy Dave's, when Herbie tries to get to the exit and blows his tire, it's the right rear. But when Lindsay is looking for a car and he drives off the block holding him up the tire is off the left rear.
Continuity mistake: When Herbie spurts the dirt onto Crazy Dave at the junkyard, the dirt on Dave's face and shoulders change frequently throughout the scene, e.g. in one shot the dirt is on his ear, the next shot it's clean.
Visible crew/equipment: At the end of the movie when Herbie has an oil spill and drives to the pit stop, as he turns, the camera pans and you are able to see the shadow of the camera, cameraman, boom mic, and the boom person on the track.
Other mistake: When the NASCAR pit crew starts working on Herbie at the barn, they initially pull a bunch of parts and tools from their racetrack trailer. One man is carrying a distinctive VW-only wheel rim, which would definitely not fit their regular NASCAR car. The decision to race Herbie had just been made, so they would not have been carrying VW spare parts yet. Nor could they have pulled one of Herbie's wheels yet since they were still carrying the jack to the barn.
Visible crew/equipment: In the opening shot, as the camera pans past a lot of junked cars, in the last car's window at the back you can see part of a camera crane and a camera lens.
Continuity mistake: During the Nascar race, Maggie passes the 48 (Lowe's) car twice in the same sequence. Only the front corner of the Lowe's car is visible when she passes it the first time. Then the shot cuts to her dad praising her on the walkie-talkie. When the shot cuts back to Maggie racing, the Lowe's car is passed again.
Continuity mistake: Trip's autograph on Maggie's helmet changes during various scenes throughout the movie.
Continuity mistake: In the NASCAR race that Herbie enters, right before he gets boxed in and they show the view from Herbie's eyes, you see Jeff Gordon's car, but the next shot when they are getting boxed in, Gordon is behind Herbie.
Continuity mistake: In the scene when Lindsay left Herbie to race in Trip's car, Herbie is shown to have a piece of clear material on his back revealing his engine. In most other shots, he doesn't have this. This is especially noticeable when he is being put into the garage, after the car crash he was put through to destroy him.
Continuity mistake: Herbie is seen from the back as Matt Dillon beats on the hood and right front fender using a tire iron. When the camera angle pans to the front, there is not even a scratch in the paint, let alone a dent. Herbie's "magic" apparently didn't prevent sheet metal damage as seen in several after-race views.
Continuity mistake: When Lindsay Lohan loses Herbie to her rival racer she throws her helmet down to her right but when its shows the view through Herbie's eyes her helmet is to her left.
Continuity mistake: When Herbie squirts oil on Maggie, the oil lands in the middle of Maggie's shirt. A couple of shots later it has moved to the right side of her shirt.
Continuity mistake: Near the beginning of the movie Crazy Dave was dragged a distance on the ground behind Herbie. When he got up he had random dirt stains on his clothes whereas there should have been dirt all over and likely physical damage to his clothes.
Visible crew/equipment: In the scene in the junkyard when crazy Dave gets hit in the head by Herbie's wheel/hub cap you can see a hand throw it.
Continuity mistake: At the end of the movie Herbie did several "doughnuts" on a large grassy area causing obvious damage to the grass, then stopped in the middle of the area he was doing doughnuts. In several subsequent shots (but not all) there was no damage to the grass.
Deliberate mistake: In the end of the NASCAR race, Tripp and Gordon get into a crash making Gordon spin, but he somehow is still able to come in second place even though every other racer was right on his back when he spun. He wouldn't have been able to regain that much speed in that short amount of time.
Revealing mistake: When Herbie is being pulled from the truck at Crazy Dave's, Herbie goes into reverse and the camera does a closeup shot of one of the rear wheels reversing. If you look carefully, you can see an extra set of small wheels behind the tyre which are obviously propping the car up enough so that the cars proper wheels will only skid and not get any traction.
Answer: It is explained in the 1997 version of "the love bug". When a scientist was building Herbie, a picture of the scientist's deceased wife who he loved very much fell into the container of molten metal. This accidental action caused Herbie to have love for any owner he has.