BMW E30 M3 Marlboro DTM Zolder 1991 Euser
Probably one of the easiest decal sets to apply. The red parts of the livery are typically airbrushed or painted. If you are not comfortable with masking the parts of the car that are not to be airbrushed you can use some bold red stripes that are included in the decal set to outline the red areas and simply paint the inside parts. No taping required, voila.
Click this to see the finished model:
Click this to download the decal set as a Powerpoint presentation, ready to be printed: