The odometer on a Dodge (Plymouth) of that model would reach all zeros at one hundred thousand miles, not one million miles.
Al's Dodge manages to travel a million miles and the odometer reads 000000.0, which will get Al a free Dodge. It rolls to the end of the driveway and Peg says the odometer now reads 000000.9 so they no longer get the free car. The Bundy's driveway is not nine-tenths of a mile long.
When Al is first shown the 1994 Dodge Viper, the boom mic clearly drops into the shot directly above him for a few seconds.