So first of all, I'm really pleased that you're continuing and that you're listening to your wife ;)
Then to the new version. Great idea with the installation, unfortunately I get the message: Files not found in the selected resolution directory
Only the two Unins files appear in the folder, the engine file does not and the GameUserSettings file is not overwritten or changed.
r.DefaultFeature.MotionBlur=1
r.MotionBlurQuality=4
r.MotionBlur.Max=0.5
r.MotionBlur.Scale=1.0
r.MotionBlur.Amount=1.0
r.MotionBlurFiltering=1
into the Engine.ini
But why should you do this :D
It not only makes the game blurry, which might be somewhat acceptable in racing games to a certain extent, but the far worse issue is that it creates artifacts around the blur, significantly reducing the quality.