Simon's original plan in the 1997 remake was that if he won the final race, he'd get to keep both Herbie and Horace so that the two could do whatever they wanted with each other. Herbie probably wouldn't do anything aggressive, but picture him in the possesion of a man who desires nothing but the worst for him, and who now has a car that has no self-control or common decency. Anything could've happened to Herbie if Simon had won.
A lot of people have come to odds with the fact that while Jim married Carole Bennett in The Love Bug, he is seen actively courting both Diane Darcy in Herbie Goes to Monte Carlo and Susan McClane in Herbie the Matchmaker. Then, Fridge Logic sets in when you can forgive Jim for courting Diane as both are fellow drivers whose cars have fallen in love instead of them, and with Herbie the Matchmaker being a TV miniseries, that can be counted as 'non-canon', thus solidifying his 'canon' marriage to Carol as of the 1997 TV Movie The Love Bug.
The Opening Montage suggests that this is in-continuity with the rest of The Love Bug series. So no one - not former opponents, not race historians, not race officials - no one recognized Herbie? Really?
As noted in Artistic License Sports, a car like Herbie would never be allowed in NASCAR due to the heavy regulations that forbid any outside-designed cars from appearing in their races (unless it was a pacecar). Furthermore, it's been shown in the past that Herbie's raced internationally in the Grand Touring and SCCA circuit, so why NASCAR of all things?