The GetCombinedForces put out wrong value when the vehicle is reversing

Reproduced 3/3 times. A similar bug occurred with PhysX ([Link Removed])

Check the function: 

FVector FSimpleAerodynamicsSim::GetCombinedForces(float VelocityIn)

if the velocityIn is negative, the value should multiply -1. Then the vehicle will get correct aerodynamic resistance.  

1. Create a new Vehicles template project
2. Open SportsCar_Pawn
3. In Components, click on Vehicles Movement Component
4. In Details>Vehicle Setup, set drag coefficient to 300
5. Compile & Save
6. PIE in VehicleExampleMap (the default editor map for the template)
7. Tap the S key to begin reversing

Actual Result: Car accelerates to mach speed, clipping through the bounds of the map

Expected Result: Car reverses slowly, as dictated by the high amount of drag. It should be similar to the Car's speed moving forward.