The yellow De Tomaso sports car has a number 6. The car that crashes was an open wheel car (Formula 1 type) with a number 96.
When Pareno and McGarrett leave from their initial meeting on the side of the mountain road, both cars squeal the tires but they were parked on dirt.
The car is supposed to be racing on Tantalus Drive which is a residential area. It indeed has many switchbacks and tight curves. The car is actually driving on Kamehame Drive up behind Koko crater in the Hawaii Kai area.