The Cadillac Northstar LMP was a series of Le Mans Prototypes built by General Motors' Cadillac brand for use in the American Le Mans Series as well as an attempt to return Cadillac to the 24 Hours of Le Mans since they first entered in 1950. The Northstar LMPs were named after the Northstar V8 engines which powered them. The Cadillac project ran from 2000 until 2002 when GM decided to cancel the project to concentrate solely on their Chevrolet Corvette program.
For 2001, the Northstar LMP was evolved in order to make it more competitive against the Audi R8s. Although still based on the Riley & Scott chassis, the bodywork was completely redesigned by Nigel Stroud. A more angular approach was used, especially on the sides of the car, with the sidepods no longer being flat horizontal but instead diving downward towards the front wheel arch. The air cooling ducts were also relocated from the side of the car, and instead placed inside the wheel wells, allowing for air exits from the wheel wells to be added to the new side. The Cadillac-theme grill was also revised, no longer being a functional open piece.
Beyond the bodywork, not much else was changed on the new car, known as the Northstar LMP01. Two of the previous 2000-spec cars were upgraded to the 2001 bodywork, while a third car was built fresh.
Source: Wikipedia (original)