The automotive industry pursues to decrease the fuel consumption of road cars. As the Brazilian government, many countries around the world incentive the industry to achieve such reduction.The purpose of this paper is an aerodynamic concept for drag reduction of fastback car. To represent a car model, the DrivAer Fastback two-dimensional profile has been adopted as baseline. The momentum transfer via blowing or suction jet applied on the rear car are investigated by means of CFD technique.From the quantitative point of view, the suction jet on rear car profile does not seem to be a way to yield drag reduction. The blowing jet at higher speed points to smaller global drag than baseline profile. Despite this positive first conclusion, the correction of drag results (removing jet momentum from the global drag) points to higher drag of profile car than the baseline car in all three cases. On the other hand, the results from the injection of momentum at lower speed suggest a reasonable application as drag reduction system. Compared to the baseline car profile, momentum injection cases at all positions indicates drag reduction. In addition, the profile drag decreases as the jet position is higher at lower jet speed.Therefore, the main contributions of this paper are (a) to expose that the best drag reduction has been evidenced via blowing jet at lower speed at highest rear car position, as well as (b) offering to automotive engineering an aerodynamic concept to improve drag reduction of road cars.