Continuity mistake: When Herbie is looking at the new yellow Volkswagen, his windshield fogs up. Then a clear spot shaped like a heart appears in the middle of his windshield. But then when it switches to the shot of him moving over to the yellow bug, the heart is at the very right of his windshield (from our view.).
Continuity mistake: When Herbie is picked up by the crane to go into the car crusher, he is missing both rear wheels, but in the previous shots he has his right rear tire still intact.
Continuity mistake: In the scene where Maggie and Kevin are washing Herbie, Herbie wiggles and shakes off the water and soap. Maggie and Kevin turn once in a zoomed out shot after Herbie splashes them, and turns a second time in a zoomed in shot of them.
Continuity mistake: In the scene after Herbie pile drives the Monster truck you can see the truck leaning to the left. But when Herbie backs off the truck it is completely straight.
Revealing mistake: When Herbie is getting unloaded from the truck in the beginning, he fights off the two guys by trying to go in reverse, but he squeals the tires. You can see the peel out tracks from previous takes when they show his tire.
Continuity mistake: When Maggie is first boxed in during the NASCAR race notice the entire pit crew is shown in a line reacting to the action. Seconds later when her father appears among them they seem to be standing in a different location with only Kevin and Ray Jr. there with him.
Continuity mistake: When Kevin and Maggie are at the fair, the smoke in the car suddenly disappears before they open the door.
Factual error: In the scene during the first race with Matt Dillon, right after he spins Lindsay Lohan out, she grabs the gear shift. We see "magical electricity" head down the shaft and forward into the engine. But, the engine on Bugs is in the back. In other scenes, it is confirmed that the front hood on Herbie gives access to a trunk and not the engine.
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.