The Vehicles
Miyuki's car is a modified Honda Today. (The Honda Today is a smaller, lighter car than the old Honda Civic. It was not sold in the USA.) This particular Honda Today has been extensively modified by Miyuki. Note the turbo inlet. The car is also equipped with "Nitro". The car is driven by Miyuki.
Natsumi's bike is a modified Suzuki GSX-R750. Notice that one of the headlights has been replaces with a police loudspeaker. The bike is driven by Natsumi.